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tll^ITED STATES 
COAST AE^D GEODETIC SURVEY 

CARLILE P. PATTERSON 

STJPEKIXTENDENT 



DEEP-SEA SOUNDING AND DREDGING 



A DESCRIPTION AND DISCUSSION 

OF THK 

METHODS AND APPLIANCES USED ON BOARD 

THE COAST AND GEODETIC SURVEY 

STEAMER, "BLAKE" 



By CHARLES D. SIGSBEE 

LIi:UTEXAXT-C(»nrANDEl{, r. S. XAVY 

ASSISTANT IN THE COAST AND GEODETIC Sl^RVEY 




WASHINGTON 

O V E R X M E X T P K I X T I X ( i OFFICE 

1880 



N,.> 



(^A" 



w^^of^r 



NOTE BY THE SUPERINTENDENT. 



OFFICE OF THE 
U. S. COAST AND GEODETIC SURVEY, 

Washington, D. C, March 15, 1880. 
This volume on Deep-Sea Sounding and Dredging lias resulted from the work 
executed during the past few years, mostly in the Gulf of Mexico. To show the char- 
acter of that work the following extract from my Annual Report of the Progress of the 
Coast and Geodetic Survey for the year ending June 30, 1879, is given. 

■•The deep-sea suuiidiuiis tlirouohcit the (iiiifof INIexi.-i,. jiaits ,,f the ( 'mihl.eiu, Sea. an, I ehaiiiiels 
anniiul Cuha. witli serial teniperature „l,servati.ms tVoii, sinfaee t,, holtnai and ,,l,s.rvatin,,s ,,t rmTents. are 
beginning to yield valuahle results towards a ni.ir,- deHiiite eoiireption of the How. mass, and dil'eetion of the 
Gulf Stream. 

•• The i.rohlem of the Gulf Stream has heen one of the principal studies of this Survey, hut for several 
years before the war, during the war. and for several years after, tin- want of means and suitable vessels sus- 
pended its investigation. After the data prevh.usly secured, those to he obtained were: 
I. Depths thr..ughout the Gulf of Mexico and the Gulf <,f Fh.riila. 
II. Temperatures from surface to h(,ftom over the same area. 

III. Character of bottom throughout the same area. 

IV. Specimens of water for analysis, from .surface to bottom, throughout the same area. 
V. Surface and un.ler Currents. 

VI. Aidnial life from surface to bottom, especially at the latter. 

-After all the data have been obtained in reference to the waters forming the Gtdf Stream, including those 
of the Gulf of Mexico and the Atlantic east of the Caribbean islands, the Stream is tii be followed to its con- 
dusions. Its oscillathms of position, ditferences ,,f velocity, m.mthly and annual, and im-rease <,f volume north 

■•Congress having l)artially provided means, the w.,rk of ..btaining data under the first tive heads was 
begun in 1^72 in the (Julf of Mexico, by Conuuander .T. A. Howell. V. S. N., A.-^sistant Coast Survey, commanding 
successively the steamers -Bache- and •Blake.' Howell su,a-essfully ran seven hundred and fbrty miles of 
sounding lines from shore out to depths of l.-20(l fathoms, by the old methods, obtaining tin- collateral data. 

••Sir AVilliam Thomscm's wire sounding apparatus having been successfully used, in tl,e PaciH,- in .lepths 

Coast Survey. At this tinn- Commander Howell was transferred to other- duty. lb- was sur,eede,l in the com- 
mand of the 'Blake' by Lieutenant-Counuand.-r C. D. Sigsbee, V . S. X.. Assistant Coast Survey, and hy that 
officer the deep-sea soundings (generally beyond one hinulred fathoms and to the depths of 2,119 fathoms) of the 
^vhole of the Gulf of Mexico were completed. He obtained at the same time full data under the first Kve head- 



-1- iS'OTE BY THE SUPEKINTENDENT. 

iiigs named. WIumi Sigslu'e saw the Tliomsqn wive sounding apparatus, he at once suggested important improve- 
ments, and devised ackhtional apparatus to relieve the strain on the wire dui'ing violent and rapid movements of 
the-small vessel. He also made other improvements so givatl.v facilitating the work that in 2,000 fathoms' depth 
the 'Blake' (of three hundred and fifty tons N. M.) was enahled. in nearly all \veatliers, to sound and obtain 
serial temperatures continuously day and night, witli a probable error in sounding not exceeding one-quarter of 
one per cent, of the depth, even during moderately severe gales. 

"The number of nautical miles of sounding-lines run by Sigsbee in the Gulf, with serial temperatures, 
was 12,766.* This gi'eat woi'k was, by the energy and unintermitting labor of Lieutenant Commander Sigsbee, 
eai'nestly supported by the officers and crew of the ' Blake,' completed early in the summer of 1878. The 
remaining part of the work; viz., collection of specimens of animal life from surface to bottom, was yet to be 

'■As naval officers are professionally neither naturalists nor geologists, I sought the services of Prof. 
Alexander Agassiz, who consented to take charge of this special part of the work, requiring only the outlay 
needful for his daily expenses. From his great experience with wire rope in mining operations. Professor 
Agassiz proposed its use for dredging purposes. Lieutenant-Commander Sigsbee, after conference Avith Professor 
Agassiz and myself, and to meet the requirements of the work hi every way, thoroughly fitted the 'Blake' for 
dredging and other piirjioses. 

"Professor Agassi/, joined tlie -Klake' at Havana in December, 1877, when Lieutenant-Connnander 
Sigsbee at once began a series of divdgings in the Gulf of ]\[exic(,, over groun.l indicated by Professor Agassiz, 
who viewed as they came from the wat.'r, took cliarge of and i)reserve(l tlie -Knds' of each haul of the dredge 

and tangles. The nets, dredgvs. Ac. had 1 ii made tV.mi tlie best models formerly u.sed in researches abroad, 

but some, not proving initirely successfu), were, at tli<- tii'st failure of each, made completely successful by sug- 
gestions from Lienteiiant-Cominamlei- Sigsbei", I'rofessor Agassi/,, Lieutenant Ackley, Master Jacoby, mid other 
otticers of the vessel. 

■■Pi'dfessor Agassiz was ol.liged to return home I'arly in March. ]H7H. A few successful hauls of the 
dredge were made after his d.'|,artiire. Lienteiiant-C'omiiiiind.-r Sigsbee in the ^ Blake ' continued, with his 
usual energy, until .luiie, adilitioiial woik- of sdiiiidings. serial tciii|icratu]'('s, Ac, under my special instructions. 

"The experience .if tliat season suggested to Lieutenaiit-Cominander Sigsbee many improvements of tlie 
machinery and facility's for dre.lging, and also an improved dredging accmnulator of his own design for rehev- 
ing tin- strain on tlie dredge rop.'. I'nder his special directions and in accordance with his plans the 'Blake' 
was ciinqiletely letifted with new reeling-engine, dredging-engine, sounding apparatus, &c,, for all the varied 
classes of work of deep-sea somiding, dredging, &c, 

'■ The term of service of Lieutenant-Commander Sig.sbee on the Survey having expired, he was relieved 
in the command of the ' Blake ' by Commander J, E. Bartlett, l^. S. N., Assistant Coast and Geodetic Svu-vey, hi 
November, 1878. 

" The discovery by the ' Cliallenger ' of submarine lakes, \vhose temi>eratures are constant to the greatest 
depths with that of the ocean at the depths of their rims, rendei-ed it more than ever imperative to determine the 
depth of the rims separating the waters of the Gulf of Mexico from tliose of the Caribbcini and its waters from 
those of the Atlantic, both to the eastward and nortliward. I assigned the 'Blake- f<,r this development, and 
Professor Agassiz again accompanied the vessel to cai'e for his own class of the work. As he was obliged to 
return home hi March, 1879 (the 'Blake' having left Washington November 28, 1878), the first work done was, 
of course, the dredging. Commander Bartlett effected this with many successful hauls, at localities indicated by 
Professor Agassiz, in depths of from ten to 2,450 fathoms, all — officers, naturalists, men — working in harmony, 
with the necessary result — complete success. Of course the dredging operations of the vessel were conducted by 

«This Is exclusive of 219 miles of inshore sounding-lines and 1,800 miles of dredging-lines in the Gulf of 
Mexico, and 2,06.5 miles of sounding-lines in the Gulf of Maine, 



XOTE BY THE SUrERIXTENDENT. O 

the officers and crew iiiuler the trireetion of Commaii<liT HaitU-tt. After the departure of Professor Agassis, 
Commander Bartlett, mider my instructions, completed all the reciuired soundings and serial temperatui'es, &c., 
between all the islands in the series fi-om Grenada to Cuba and Jamaica, making no soundings in the Gulf of 
Mexico. The 'Blake' arrived at New York on May 28, 1879. 



■• Without specifying the great results obtained fi-om i 
ring with some gratification to the fact that in the small steamer 'Blake/ of only three hundred and fifty tons 
burthen, N. M., under the energetic and skillful commands of Lieutenant-Commander Sigsbee and Commander 
Bartlett. with a ftill complement of forty-fire including oflicers and crew, more rapid work was done than had 
been accomplished with the old methods and appliances by the ■ Challenger,' a vessel of over 2,00(1 tons Ijnvtlien. 
with a complement of twenty-nine naval and civil oificei-s and a correspondingly large crew." 

There being no special publications with detailed instructions on the .sy.st€ms and 
methods adopted for deep-sea sounding and dredging, although much attention is now 
paid by all maritime nations to the subject, it has been thought advisable to publish the 
methods used on board the "Blake." These methods, in even so small a vessel as the 
" Blake," have been prosecuted with celerity, ease, and precision, showing that deep-sea 
work has become nearly as ready of accomplishment as ordinary littoral soundings. 

Carlile jP. JPatterson, 

Superintendent TJ. S. Coast and Geodetic Survey. 



CONTENTS. 



CHAPTER I. 

INTRODUCTIOX. 



The authors connection with the "Bhike" : Causes leading to the publication of this hook.— The work 
of the •'Blake."— Remarks on the utihty of piano-for^te wire for sounding- purposes.— Description 
of the '• lilake " : Duties of officers and crew : Routine.— Officers of the ■■ Blake " and their civilian 
associates.— Stati.«tics of work done liv the "Blake" 



CHAPTER II. 

SOL^^DING-WIRE. CORRECTION-CITJVE. SOUNDING-RODS; AND SINKERS. 

Ro])e for sounding purposes. — "Wire for sounding purposes. — Description (jf piano-forte wire used for 
sounding pnqroses.- Methods of splicing the wire.— Preservation „f tlie ^vire when not in use.— 
Winding off wire for use or transfer.- Stowage and supply of wii'e ; a suggestion.- Guiding the 
wire in reeling up and unreeling.— Pieservati<iu of the wire in use: The tank.— Kinking.- Wire 
tests, and working strain.— TliJ rorrectimi-curve.— Sounding-rods.— Description of the modified 
Belknap sounding-cylinder X... -2. fitted witli Sigsbee's detacher.— Working of the sounding-rod.— 
Notes on the consti-uctimi of tlie sniuiding-rod. — Requirements for a perfect sounding-rod. — General 
remarks on sonnding-m.ls and ileta.lirrs.— Heavy sinkers for detaching.— The gas-pipe sounding- 
rod.— Light-weight suunding-lHad fnl- recovery ' 

CHAPTER III. 

THE SOITNDING-MACHINE AND ITS USE. 

Description of the original service macliine for sounding with ]iiano-forfe wire. — Attempts tending 
towards the improvement of the sounding- reel. —The stray-line, and the method of sjdicing it to 
the wire.— Remarks on the Sigsbee machine for scumding witli wire.— Dcsciiption of the latest form 
of the Sigsbee sounding-niacliine.— To take a scuniding witli tlie Sigsbe,. s,„m.ling-machine.— 
Keephig a time-record of soundings, witli example.— Times ,,f various rusts taken l.y tlie •■ Blake " 
with sixty-poimd shot-sinkers.— Haiding back a lead sinker; examide.— Times nf vaii..„s casts 
taken by the -Blake" with lead sinkers.— The damp and its use.— Stations at the M,nnding- 
machine.— Accidents.— Position for the sounding-machine : Laying the vessel for sounding.— Keel- 
ing inAvhile steaming ahead. — Experiment in towing wire from the '-Blake." — Description of a 
new steel reel, with remarks ou crushing force. — Reeling-engines and accessories for sounding pur- 
poses 



CONTEKTS. 
CHAPTER IV. 



WATER SPECIMENS. DENSITIES, TEMPERATURES. AND CURRENTS: APPA- 
RATUS AND METHODS. 

iliiii;iti(iii of \vater and soil specimens. — Remarks on "water-cujjs, -with special reference to the Sigs- 
liee Avater-cup. — Descriptioii of the Sigshee water-cup. — Working of the Sigsbee water-cup. — 
Water dt'iisities: how oli^erved. — Hilt;ard's ocean f^alinonieter (areometer). — Hilgard's optical den- 
simeter for nc-aii water.— Serial watei- temiieratures ; liow taken.— Description of tlie Miller-Cas- 
eUa deep sea thernH.niet,.r.— Remarks ((inreriMii- tlie :\Iiller-Casella thermometer.— Description of 
Negretti and Zan,l.,'a-s deep-s.-a tlHTiiMuneter.— K.Muarks concerning Negretti and Zamhi'aV tl,er- 

witli a standard.— Determination of surface and sub-surtace currents.— Remarks ou the conditions 
attending deep-sea work. — Strength of springs 



CHAPTER V. 

DREDGING AND TRAWLING ; APPARATUS AND METHODS. 

Fitting the "Blake" for dredging.— The first dredging cruise.— The second dredging cruise.— General 
remarks. — Dredges: the old pattern and tlie iiii)iroved jiattern. — Tlie improved trawl. — Weighting 
dredges and trawls ; tangles. — The tangle-bar drag. — Tow-nets or drag-nets. — Netting for dredges 
and trawls. — Tubs and sieves. — Steel-wire dredge-roi)e. — The dredge-reel. — Tlie steam hoisting 
and winding engines. — The swinging-boom. — The accunudator or dynamometer. — The iron snatch- 

APPENDIX TO CHAPTER V. — Appakatus of the Fish Commissiox. — The rake- 
a.vdge.- The tangles.— The check-stop.— The cradle-sieve.-The table-sieve 

CHAPTER VI. 

NAVIGATION AND RECORDS. 

Devising a systematic record. — T^Hiat constituted the record. — Explanation of record forms. — Scheme 
of navigation record.— How to keep tlie ].lotting-form ; its use.— The archives.— The plotting- 
truciug, and the sounding-sheet. — Details of tlie plotting of line S; establishing the positions. — 
Details of the plotting of line S (continued) ; plotting the soundings.— Remarks and suggestions 



SUPPLEMENT. 



Sigsbee machine for sounding with wire; pattern of 1881. — Gravitating or collecting trap for obtaining 
animal specimens from intermediate depths. — Pressure errors of Miller-Casella thermometers 



PLATES IN SUPPLEMENT. 

42. Sigsbee machine for sounding with wire; pattern of 1881 

43. The same 

2 D S 



LIST OF PLATES. 



1. View of the "Blake" (frontispiece) 

2. Miller-Casella thermometer case, fitted with Sigsbee's spring chniip ; cuil (if sounding-wire; sound- 

ing-rod 

■y 3. Miller-Casella thermometer case, fitted with Sigsbee's spring cl:nnp ; sounding-rod 

,. 4. Showing some of the causes, probable and real, of the occasional failures <,f sinkers to detach.... 

, 5. Ciu-rent cans or floats ; sounding-lead fitted with Stellwagen specinieu-oup 

/ 6. Showing general form and working of Sir William Thomson's sounding-machine, as used on board 
the "Blake "during her first season in the Gulf of Mexico 

^ 7. Experimental form of Sigsbee machine for sounding with wire 

i^8. Latest form of Sigsbee sounding-machine as used on board the " Blake," rigged for paying out 

'^ 9. The same from another point of view 

^10. The same from still another point of view 

1^11. Sigsbee sounding-machine, rigged for reeling-in, with strain-pulley brought into use 

^''l2. The same machine folded for ^transportationr ". 

^,13. The same machine in j-osition ; run out for work 

""14. The same machine in position; run in , 

'15. The same mnchine in position ; run out ; from another point of view 

' 16. Mechanical drawing of new steel reel for sounding with wire 

^\1. View of same reel 

'' 18. Mechanical drawing of small steam-engine for use in connection with sounding-machine 

^ 19. Simple form of water-specimen cup used by the Coast Survey 

20. Sigsbee water-specunen cup, for getting specimens from various depths at a single haul 

"^ 21. Case for Negretti and Zambra's deep-sea thermometer ; Negretti and Zambra's deep-sea thermometer ; 

Miller-Casella deep-sea thenuometer 

■^22. The same appliances 

^ 23. Negretti and Zambra's deep-sea thermometer in use 

- 24. The "Blake;" dredging-gear ready for work 

■ 25. Old style of dredge ; improved dredge 

- 26. Plan of old-style trawl ; plan of improved trawl 

27. View of improved trawl ready for use 

28. Improved tra-svl shown as having " tripped " after fouling with rough bottom 

29. Plans of deck and apparatus of the " Blake " as fitted for dredging cruises 

■ 30. View of the " Blake's" deck, looking forward 

' 31. View of the "Blake's" deck, looking aft 

32. Forward side of dredge-reel and its engine, showing dredge-rope ; 

' 33. View of main hoisting-engine from starboard side 

34. Mechanical drawiims of iron snatch-block for dredge-rope, and of improved accumulator for 
'li--'¥»K - , 

■ 3.5. Illustration of the plotting of a hue of s.nmdings 

- 36. Mechanical drawings of the " Blake's " form of Sigsbee sounding-machine 

- 37. Continuation of the^same 

38. Continuation of the same, showing odometer and register 

39. Mechanical drawings of Sigsbee's detacher used in coniu-ction with a modification of Captain Bel- 

knap's sounding-cylinder No. 2 

40. Mechanical drawings of Sigsbee's water-specimen cup 

41. Curve for correcting reading of register placed on axle of sounding-reel 

9 
2 DS 



LIST OF WOOD-CUTS. 



A. — Comparative size of hemp rope and steel wire for souiuliiig p 

B.— Brooke's sounding-rod and detaclier 

C— Belknap's sounding-cylinder No. 2 

D.— Hilgard's ocean salinonieter (areometer) 

E. — Hilgard's optical densimeter for ocean water 

F. — Apparatus for fixing the boiling-point of thenr 

G. — Comparative size of dredge-ropes 

H.— Eake-dredge. (Fish Commission) 

I.— Tangle-bar. (Fish Commission) 

J. — Check-stop. (Fish Commission ) 

K.— Cradle-sieve. (Fish Conmiission) 

L.— Table-sieve. (Fish Conmiission) 

M.— Table-sieve. (Fish Commission) 



LIST OF FORMS. 



1. Sounding- time-book 

2. Serial temperature-book 

3. General recoi-d form 

4. Supplementary record form 

5. Rough book of observations. .. 

6. Navigation form 

7. Navigation form 

8. Navigation form 

9. Navigation form 

10. Navigation fonn 

11. Navigation form 

12 Navigation form 

13(A). Plotting form (prepared) .. 

13 (B). Plotting form (completed) . 

14. Temperature-curves 

15. Section, and temperature-curves 

10 



DEEP-SEA SOUNDING AND DREDGING. 



CHAPTER I. 
INTRODUCTIOK 



THE AUTHORS CONNECTION WITH THE "BLAKE . CAUSES LEADING TO THE 
PUBLICATION OF THIS BOOK. 

In August, 1874, the "Blake," commanded by Commander John A. 
Howell, U. S. N., Assistant in the Coast and Geodetic Survey, was pro- 
vided with one of Sir William Thomson's sounding-machines for wire, 
modeled after the original service pattern (Plate 6), but, unfortunately, 
the nature of the work performed by the "Blake" thereafter, while under 
the command of Commander Howell, gave opportunity for only seven 
soundings with the wire. It is to be regretted that the machine did not 
reach Commander Howell at an earlier period of his work, as doubtless, 
had he seen more of it in actual use, many improvements would have 
resulted from his experience and well-known ingenuity. 

In October, 1874, after four months of special work in the office of 
the Coast and Geodetic Survey, at Washington, during which the machine 
shown on Plate 7 was devised, draughted, and put in the hands of the 
mechanics, the Superintendent transferred me to the "Blake" as execu- 
tive officer. The services of Commander Howell being needed in an 
important position at the Naval Academy, he was detached from the. ves- 
sel at New Orleans in December, 1874, several months sooner than had 
been anticipated, and was succeeded in the command by the writer. 

The adoption of wire for sounding purposes opened the way to more 
extended operations than had previously been attempted by the party. 

For four years the vessel continued under my command, engaged in 
deep-sea work. When the time had arrived for my return to regular naval 



12 DEEP-SEA SOUNDING AND DKEDGING. 

duty, the Superintendent of the Coast and Geodetic Survey was kind 
enough to express a belief that a description of the methods and appliances 
used on board the "Blake" would be worthy of publication, and under his 
direction this book has been written. The plan of the book involves a 
double purpose: first, to describe our methods and appliances, chiefly from 
a mechanical standpoint, in order that any deserving features may become 
generally known; and, secondly, to provide, in a measure, a guide for those 
who may hereafter have charge of the deep-sea work of the Coast Survey. 

A question may naturally arise as to the considerations which would 
authorize a notice of the methods and appliances of the "Blake's" party. 
To this it is replied — 

We were one of the first, after Sir William Thomson, and Capt. George 
E. Belknap, U. S. N., to use piano-forte wire for sounding purposes, and we 
probably continued its use for a longer time than any other organization. 

The "Blake" is the only vessel that has ever been fitted out with 
wire rope (the suggestion of Prof. Alexander Agassiz) for deep-sea 
dredging and trawling. 

But httle has been published concerning the use of wire for sound- 
ing; and of wire rope for dredging, nothing, in fact, excepting in a gen- 
eral account of the " Blake's" dredging work by Professor Agassiz. 

Nearly all the apparatus for sounding and dredging used on board the 
"Blake" is new or modified from previous forms, and is peculiar to that ves- 
sel, the water-cup (Plates 20 and 40) being the first and only instrument 
in the field for the performance of the complex work aimed at in its design. 

These appliances, which are intended to effect an advance in accu- 
racy or in celerity of operations, and to secure ultimate economy, have 
been well tested in actual service, and are believed to have accomplished, 
at least in some degree, the object sought. 

Having had unusual facilities, in connection with continuous work, 
our methods were perhaps more systematic in certain directions than are 
generally followed by parties or organizations for the prosecution of deep- 
sea work. 

Our navigation-record was comprehensive, and adapted to future 
revision or verification. 



INTRODUCTION. 13 

THE WORK OF THE " BLAKE." 

The Coast and Geodetic Survey is entitled by law to the services of 
naval officers and men for its hydrographic parties. For the time being, naval 
officers on Coast Survey duty are as much a part of that organization, and 
as fully under the control of the Superintendent in all matters connected with 
the work, as the corps of civilian assistants. Excepting during the first two 
years of my command, when the surgeon and the engineer were civilians, 
the party on board the "Blake" was composed of naval officers, and of men 
enlisted under naval shipping-articles. In general terms, the work required 
of the party was to fulfill, in the Gulf of Mexico, a scheme of the Superin- 
tendent, having for its object the examination of certain physical conditions 
of that body of water throughout its whole extent, those of first importance 
being the depths and temperatures. Our operations in the Gulf of Maine 
were of similar intent, but on a smaller scale. The execution of the work, 
embracing observations for depths, serial water temperatures and densi- 
ties, and for currents when possible, together with the collection of speci- 
mens of the bottom soil or deposit, and of surface, bottom and intermedial 
water specimens, was intrusted to the naval officers on board, under the 
direction of the Superintendent, who was cognizant of every important act 
of the party, and who, with much kindly interest, noticed its workings even 
to the smallest essential details. In this direction the Superintendent was 
assisted by Commander E. P. Lull, U. S. N., Hydrographic Inspector of the 
Coast and Geodetic Survey. Afterwards, during the first three months of 
my last season, we were most pleasantly associated with Prof. Alexander 
Agassiz and his assistant, Mr. S. W. Garman, for the dredging operations 
which then became part of our work. 

A short sketch of the work performed by the "Blake's" party in 
each season will perhaps not be amiss.^ 

During the winter season of 1874-'75, after two months of special 
work, we ran a number of lines of soundings radiating from the Passes 
of the Mississippi Biver and extending a distance of one hundred and 
twenty miles seaward. The work was brought to a close by running a 
line from the Southwest Pass of the Mississippi Biver to the mouth of 



14 DEEP-SEA SOUNDING AND DEEDGING. 

the Rio Grande, four hundred and sixty miles, and thence another, nearly 
east, across the Gulf of Mexico, seven hundred and sixty miles, to Tor- 
tugas, the westernmost of the Florida Reefs. Total number of miles of 
sounding-lines in deep water run during the season, 2,505. 

During the summer season of 1875 we ran a number of lines in and 
across the Gulf of Maine in various directions. Total number of miles 
of sounding-lines for the season, 2,065, 

In the winter season of 1875-76 we ran a system of east-and-west 
lines across the great bank west of the Florida Peninsula, and in the con- 
tiguous deep water. These were followed by others of less length on the 
northern portion of the bank, and by several extending well out to sea 
from points adjacent to the delta of the Mississippi River. The season 
was closed by running a line from the South Pass of the Mississippi 
River nearly due south to the Yucatan Rank, and another from Alacran 
Reef, on that bank, to Tortugas, Total number of miles of soundings 
for the season, 2,519. 

We began the work of the winter season of 1876-77 by running a 
line extending from Cape Romano, on the west coast of Florida, to a point 
two hundred and fifty miles due west, and thence another line due north, 
about an equal distance, to the coast not far east of Pensacola, Fla. Then 
followed an unbroken set of lines which, beginning near Pensacola and 
ending at Timbalier Island, formed nearly the three sides of a rectangle 
and crossed all the lines previously run on the slope of the Mississippi 
Delta. A continuation of the deep-sea work completed a system of east- 
and-west, north-and-south, and normal lines from the coasts of Texas 
and Louisiana. Refore the end of March we had completed all that had 
been planned by the Superintendent for the whole season. Additional 
work was given us, as planned by the Superintendent, and, accordingly, 
we ran a set of sounding-lines from the Southwest Pass of the Missis- 
sippi River to the northwest edge of the Yucatan Bank; then, in irregu- 
lar order with regard to locality, but according to the advantages to be 
derived from winds and currents, we ran a number of east-and-west lines, 
which sufficiently covered the ground from the southernmost part of the 
Gulf of Mexico to the completed lines off the coast of Texas and from 



INTRODUCTION. 15 

the western shores of the Gulf to the Yucatan Bank, or to our finished 
work in the middle of the Gulf. Forty-six hundred miles of steaming 
on the additionally-prescribed work, much more than half on sounding- 
lines, brought us back to New Orleans, after an expenditure of one 
hundred and sixty-three tons of coal on the cruise; all of the work 
throughout that part of the Gulf of Mexico west of the meridian of 89° 
having been completed. A series of homeward-bound lines, in the east- 
middle part of the Gulf, brought the season's operations to a conclusion, 
and completed, as previously laid down by the Superintendent, the whole 
scheme of work for the Gulf of Mexico, exclusive of the Straits of Florida. 
Number of miles of sounding-lines run during the season, 6,426, with an 
average of one sounding to every six and one-fourth miles, over forty of the 
casts having been in depths exceeding 2,000 fathoms. In carrying out 
this season's work the "Blake" had encountered fifteen or more gales at sea. 

The first three months of our winter season of 1877-78 — December, 
January, and February — were devoted to dredging in localities indicated 
by Professor Agassiz; in the Straits of Florida to the westward of Havana 
and Key West, on the eastern and northern slopes of the Yucatan Bank, 
on the western slope of the Florida Bank, and on the southern slope of 
the -Mississippi Delta. Early in March Professor Agassiz returned to his 
home, and shortly afterwards the systematic sounding and serial tempera- 
ture work of the party, which we had not attempted while the naturalists 
were on board, was resumed. A number of lines of soundings were then 
run, to the westward of Havana and Key West, across the Straits of Florida 
and the Yucatan Channel in various directions, completing the Superintend- 
ent's scheme for the whole Gulf of Mexico. Number of miles on dredging- 
lines, 1,800; number of dredging-hauls, eighty-two; number of miles on 
sounding-lines, 1,316. During this season the longest piece of hemp rope 
on board the vessel, for sounding or dredging purposes, was an ordinary 
coasting lead-line. Soundings were made with piano-forte wire, serial 
water temperatures were taken with small steel rope, while hauls with 
the dredge and trawl were made with steel rope of a larger size. 

On the arrival of the vessel at New York, after the winter season of 
1877-78, having performed four years of service on the Coast Survey, my 



16 DEEP-SEA SOUNDING AND DEEDGING. 

detachment therefrom and return to regular naval duty became necessary; 
it being determined, however, that I should first superintend the prepara- 
tion of the "Blake" for the work of another sounding and dredging season. 

On November 1, 1878, the fitting of the '* Blake" having been about 
completed, Commander John R. Bartlett, U. S. N., succeeded me in com- 
mand of the vessel. Since then the party has executed another season's 
work, in the Caribbean Sea and Passages, the time having again been 
divided so as to permit several months of dredging in advance of the reg- 
ular party work of deep-sea soundings, serial temperatures, &c. In the 
dredging operations, Prof. Alexander Agassiz and his assistant, Mr. S. W. 
Carman, were again associated with the party. For the second dredging 
cruise we concurred in a plan of fitting the vessel for dredging to accord 
with the experience gained on the previous dredging cruise. The plan 
was approved by the Superintendent, and under the management of Com- 
mander Bartlett and the officers of the ''Blake," with the advice and 
suggestions of Professor Agassiz and Mr. Carman, the mechanical opera- 
tions of the season have marked a definite advance in this kind of work. 
In addition to the new dredging arrangements, the vessel was supplied 
with a new sounding-machine, a later form of my modification of Sir 
William Thomson's deep-sea sounding-machine (Plate 8) . 

In the sounding and other party work, under Commander Bartlett, 
which succeeded the dredging operations, the success was equally marked. 
In the entire work of the season, comprehending two hundred and twenty- 
five hauls with the steel dredge-rope and six hundred and sixty-four 
soundings with wire, there were but few accidents of any kind, and none 
due to imperfect working of the appliances. 

REMARKS ON THE UTILITY OF PIANO-FORTE WIRE FOR SOUNDING PURPOSES. 

After the achievements of Captain Belknap, the success of Com- 
manders Miller, Dewey, Schley, and Philip, and Lieutenant-Commanders 
Green and Gorringe, of the Navy, the continuous and successful work by 
Commander Bartlett and myself in the Coast Survey, and the work done 
under the auspices of foreign governments or companies, it would seem 
that no further evidence is required to demonstrate the superiority of 



INTEODUOTION. 17 

wire over rope for deep-sea sounding ; yet, as these results, however sat- 
isfactory, may not convince persistent doubters, some particulars are 
given that may seem more tangible. 

First, it can be shown that the excess of iron for sinkers, thrown away 
in sounding with rope, if saved, would pay for all the probable losses of 
wire, sinkers, and instruments in sounding with wire. For the moment, let 
us take a view of rope so favorable as to assume that it will never part, 
hence will last indefinitely, and will never cause the loss of instruments. 

Iron for sinkers expended in 20 soundings with vupe, in deptlis of 2,000 fathoms (200 pounds eacli 

cast), 4,000 pounds, at 2| cents per pound |100 00 

Again, let us take so very unfavorable a view of wire as to assume 
that it will part at every twentieth cast in depths of 2,000 fathoms, losing 
the wire, a sounding-rod, and a thermometer. 

Iron for sinkers expended in 20 soundings with wire, in deptlis of 2,000 fiithonis (60 pounds eacli cast), 

1,200 pounds, at 2i cents per pound |30 00 

Cost of 2,000 fathoms sounding- wire, 29 pounds, at 75 cents per poinid 21 7.5 

Cost of one eliiborately finished sounding-rod 14 50 

Cost of one thermometer 12 00 

Total cash expenditure, shoukl all this material he lost |78 25 

If, besides this, we were to lose an elaborately finished water-cup 
costing $2o, the total cash expenditure would be $103.25. 

If, in the above computations, we take the cost of the iron sinkers at 
three cents per pound, which is nearer the mark, we find the cost of iron 
expended in the rope soundings to be $120, and the total cash loss in the 
case of the wire $109.25, including the water-cup. 

Contrary to the assumption, rope sounding-line does in reality part, 
much of it being lost in extended work, involving the loss of instruments. 
If not lost, rope will deteriorate in use. 

In the six hundred and sixty-four casts with wire by Commander 
Bartlett, in depths varying from one hundred fathoms to 3,000 fathoms, 
the total losses of instruments and material, exclusive of iron sinkers, but 
including leads, could not have exceeded $150. At every cast a ther- 
mometer was used for bottom temperature, and in some cases a water-cup 
was sent down. The total loss of wire was 2,400 fathoms, due once to 
the rare accident of fouling on the vessel's copper sheathing, and once to 
the lead fouling on a coral bottom, on which everything fouled. Captain 
3 D s 



18 DEEP-SEA SOUNDING AND DEEDGING. 

Belknap, during the progress of his deep work in the Pacific, took one 
hundred and twenty consecutive casts without accident. Commander 
Schley lately ran a line of soundings across the South Atlantic, from St. 
Paul de Loando, Africa, to Cape Frio, Brazil, taking thirty-eight casts in 
depths from one hundred fathoms to 3,284 fathoms, without loss and 
nearly without accident. In a record of naval sounding work it is shown 
that Commander Philip recently took eighty-six consecutive casts in 
depths up to 3,000 fathoms without a case of parting the wire. On board 
the "Blake" we managed to keep the same piece of sounding-wire in use, 
as occasion presented, for a whole year, sounding day and night, and some- 
times under circumstances in which the vessel rolled repeatedly 30° and 
even 35°, the machine being in charge of officers changed in regular sea 
watches. With wire we have hauled back a fifty-seven-pound shot-sinker 
from a depth of 1,800 fathoms by steam, and have sounded day and night, 
in seas three hundred feet from crest to crest, in depths of 1,200 fathoms, 
using and recovering a thirty-four-pound lead, and hauling back by steam. 

It is believed that in point of accuracy and celerity the advantage of 
wire over rope has never been questioned. 

Our casts in the swift current of the Gulf Stream were, to all appear-, 
ance, as successful as elsewhere, and they presented no difficulties worthy 
the name. 

DESCRIPTION OF THE " BLAKE " I DUTIES OF OFFICERS AND GREW: ROUTINE. 

The " Blake" was built for the special work on which she is employed. 
She is of three hundred and fifty tons 0. M., one hundred and forty feet 
in length on the load line, twenty-six feet six inches beam, and has a deep 
draught of eleven feet. Her engine, which is compound, of about seventy 
nominal and two hundred and seventy actual horse-power, gives her a 
speed of eight knots, under ordinary circumstances, for an expenditure 
of four tons of coal in twenty-four hours; and she may be pushed to 
nine knots under steam alone. Under both sail and steam she has been 
known to maintain a speed of ten and a half knots. Her bunkers will 
accommodate coal for thirty-eight days' steaming, at a daily expenditure 
of four tons. The rig is that of a fore-and-aft schooner, and consists of 



INTEODUCTIOK. 19 

foresail, mainsail, jib, fore-stay sail, and fore and main gaff-topsails. Aft 
on the main-deck are spacious and well-ventilated quarters for the offi- 
cers. Forward of the wardroom, on the same deck, is a continuous line 
of midship houses, reaching nearly to the foremast and forming the en- 
gine-room, boiler-room, galley, pantry, draughting-room, lamp-room, and 
mechanics' sleeping-room. The arrangement of the main-deck houses 
leaves, on either side, a wide gangway, ventilated and lighted along its 
whole length through large square ports which can be kept open at sea 
in any ordinary weather. Beneath a sufficiently large berth-deck is a 
good-sized hold with tanks for holding 2,500 gallons of fresh water, while 
under the cabin and wardroom, and accessible only from those apart- 
ments, are large store-rooms. The upper-deck is flush, and gives ample 
room for the reception of all the necessary machinery and gear. 
Plate 29 shows the upper-deck plan. 
A. — Main hoisting or reeling engine. 
B. — Dredge-reel. 

C, C, C, &c. — Iron leading-blocks for dredge-rope. 
D. — Dredge-boom. 

E.^Small reeling-engine, connected with dredge-reel. 
F. — Reel for steel-wire temperature-rope. 
G. — Sounding-machine. 

H. — Small reeling-engine for sounding-machine. 
i. — Fore hatch. 
j. — Foremast. 
k. — Pilot-house. 
/. — Draughting-room skylight. 
7?i.— Galley skylight. 

n. — Boiler-room skylight, and smokestack. 
0. — Engine-room skylight. 
]). — Mainmast. 
q. — Wardroom skylight. 
r. — Cabin and wardroom companion-way. 
s. — Cabin skylight. 
t. — Rudder-head. 



20 DEEP-SEA SOUNDING AND DREDGING. 

The machinery will he explained hereafter. 

The complement of officers, exclusive of the chief of the party, was 
as follows : One lieutenant as executive and navigator, one lieutenant or 
master as assistant navigator, three masters or ensigns as watch officers, 
one engineer, one surgeon, and one captain's clerk. The last two, in 
addition to their legitimate duties, acted as recorders on deck. The force 
of forward hands, all told, was thirty-six men, which gave for deck duty 
eight men in one watch and nine in the other; — the boatswain's mate 
being the odd man. The work required of each deck-watch at sea was ^ 
to fill the stations for running the sounding-machine, getting tempera- 
tures and water specimens, making current observations, attending reel- 
ing-engines, making and reducing sail, steering, keeping lookout, &c. This 
force was adequate until the first dredging cruise, when six extra hands 
were shipped to turn the crank of the dredge-reel. For the second dredg- 
ing cruise, steam having been applied to the dredge-reel, the regular com- 
plement did not need to be augmented, it being possible to haul in depths 
of 3,000 fathoms with three men, every detail, including steering, being 
executed. For working the main engines the "Blake" had three machinists 
and six firemen. The number of the latter was at one time reduced to 
three for part of a season, but this reduction providing for no substitutes 
in case of sickness, the original complement was afterwards restored. 
All the reeling-engines were managed by the deck-hands. Idlers were 
never called on to assist in any part of the hydrographic work. 

Duties were divided among the officers as follows: The executive offi- 
cer was charged with the care of the chronometers, compasses, and other 
delicate instruments. Besides having the usual navigating work to do, he 
plotted the lines of soundings and superintended the preparation of the 
records in every particular. The assistant navigator aided in the navi- 
gating work, took current observations at sea, and, on the arrival of the 
vessel in port, revised the computations of all observations for position. 
This officer and the three watch officers had each to care for certain 
appliances or gear, and to keep a record of data concerning them. The 
Avatch officers in rotation had charge of the deck, where they managed 
the vessel and directed the mechanical part of the hydrographic work. 



iKTEODUOTIOiT. 21 

The recorders assisted the officer of the deck in keeping the deck-record 
required by the several forms to be shown hereafter ; they were unavoid- 
ably pushed to their utmost in prolonged work, their duties forcing them 
to stand watch and watch, which they divided, by choice, into six-hour 
intervals. The engineer helped greatly by draughting the profiles and tem- 
perature curves. No officer was excused from party work by other duties. 

With two officers navigating, three doing deck duty, and two record- 
ing, the labor seemed fairly divided when the nature of the services to be 
performed was considered. Had the sounding-lines run by the "Blake" 
been of much greater length, a third recorder would have been necessary. 
With an increased complement of officers, from which to make the detail, 
a better plan, in one respect, would be to put all instruments, appliances, 
and gear, excepting chronometers, compasses, and the like, under the 
special charge of one officer, whose chief duty it would be to have them 
kept in good order and repair. 

An overcast sky precluding observations for position, the proportion of 
favorable working weather during each season was not great, and we were 
sometimes compelled to remain in port many days together. Bearing this 
in mind, all hands cheerfully acquiesced in the demands made on them 
when at sea. The longest continuous run that we ever made on sounding- 
lines occupied eleven days, although that length of time was nearly equaled 
on several occasions. These long runs were sometimes executed under 
such trying circumstances of wind, weather, sea, and current as to impose 
much mental strain on the officers and to call forth all the endurance of 
the crew. At sea, everything had to give way to the work in hand. If the 
vessel did not look pretty, we concluded that we could not help it, and 
complacently looked forward to a higher standard on our arrival in port. 
It was generally understood and appreciated by all on board that mistakes 
through carelessness ought not to be tolerated, and that strictness should 
rule always in matters immediately connected with the special purpose of 
our party. In port, on the contrary, the fullest liberty of action, not at 
variance with good order and the interests of the work, was allowed. 

The port duties were, in brief, to plot the work, to complete the rec- 
ord, and to "straighten up" the vessel. Whenever it was practicable we 



22 DEEP-SEA SOUNDING AND DEEDGING. 

made fast to a wharf, with a view of lessening hoat work and of affording 
facihties for recreation. The watch officers tlien w^ent into ''day's duty/' 
but were not required to be continuously on deck unless something 
special or important made their presence necessary, the ordinary routine 
being under the immediate charge of the quartermaster. 

Assuming early morning as a starting-point, the usual daily routine 
of sea duty on board the "Blake" was about as follows: 

While the stars were still bright the navigators were up and ready, 
and, from the first well-defined appearance of the horizon until the disap- 
pearance of the stars, the best observations that could be had for the ves- 
sel's position were obtained. If a sounding was being taken at twilight, 
as frequently happened, we endeavored to time some of the observations, 
so that the position given by them might be coincident with that of the 
sounding. Then the navigators retired to the draughting-room to effect the 
computations, the result of which was anxiously awaited to find if the 
vessel had been drifted much away from the line during the night. The 
soundings, which had been carried on all night, were continued through the 
day at specified intervals of distance ; and at occasional sounding stations, 
generally according to schedule, serial water temperatures and serial water 
densities were noted. When current observations were in order they came 
immediately after the sounding, unless serial temperatures were required 
also, in which case the latter took precedence. At every sounding the sur- 
face-water temperature, and certain other data, as shown on Form 3 in 
another chapter, were secured. A deck-board, having fastened to one side 
of it a General Record, Form No. 3, and to the other side a Supplementary 
Record, Form No. 4, for the reception of details relevant to the columns, 
was kept in the pilot-house under the care of the recorder. Although that 
officer made all the entries, excepting those requiring a nautical judgment, 
the officer of the deck was the responsible person, and as such w^as obliged 
to affix his initials to the record at each station. Usually at every sound- 
ing, when the run between soundings occupied an hour or more, observa- 
tions for position were taken if possible, and at evening twilight the pro- 
ceedings of the corresponding morning period were repeated. Favorable 
opportunities for finding the position afterwards were made the most of, but. 



rNTEODUCTION. 23 

as a matter of course, tlie work of the navigators was lessened at night by 
the comparative rarity of chances for accomplishing anything within the 
province of their office. In_every other respect our operations, whether 
for depths, currents, or temperatures, went on the same at night as by day, 
there being no falling off in their amount or character on account of 
darkness. Dredging, when it became a part of the work, was likewise 
continued at night; but runs between the stations were made after dark 
rather than in the daytime, when our movements could be so managed. 

The following is a specimen, given from memory, of the kind of gen- 
eral order that I issued at the beginning of the season's work, for the 
guidance of officers of the deck: 

General Order. 

In depths less than one hundred fathoms, sound with rope ; in deeper water, sound with wire. For 
depths no greater than 1,000 fathoms, employ the thirty-four-pound lead and haul it back ; for depths exceeding 
that, use shot-sinkers and detach them on the bottom. Tlie sounding intervals will be as follows : In depths less 
than five hundred fathoms, five miles: between five hundred and 1,000 fathoms, seven miles; between 1,000 
and 1,500 fathoms, ten miles ; greater than 1.500 fathoms, fifteen miles. Make it a serial temperature station at 
the terminal soundings on all lines; also, at every fourth sounding when the interval is five or seven miles, and 
at every third sounding whew it is ten or tifteeu miles. At all temperature stations the usual party work, under 
the following heads, will be fully executed: Depth of water: serial temperatures and water specimens, includ- 
ing those at the surface and bottom; density and correspoiuling temperature of water specimens; bottom-soil 
specimen and all water specimens bottled and saved for examination. The appended table gives the serial depths 
from which temperatures and water specimens are required. 

At every sounding the temperature of the surface water will be recorded, and that of the bottom water 
likewise when Avorking in less than 1,000 fathoms over slopes. In getting the sub-surface water temperatures 
allow seven minutes after the final stoppage in which to let the thermometers register. Get the bottom tempera- 
tures and water specimens Avith the aid of the wire or rope that is being used for the sounding. 

Water-cups intended for use will be adjusted and in readiness before arriving at the station. Thermome- 
ters will be set the last moment before they are fastened to the rope or wire, and the readings noted at once when 
the instruments are removed from the rope on coming out of the water. The results of the serial temperature 
observations will be carefulh^ scrutinized by the officer of the deck, and any readings that are apjiarently fiilse, 
or are contrary to what was anticipated, will be at once reported to the commanding officer. At each tempera- 
ture station the approximate highest point at which the temperature of 39^° occurs — the normal tem})erature of 
the deep Gulf water — must be ascertained in order to make the series complete. Record the character of the 
bottom-soil specimens at all soundings. Save the specimen for examination at serial temperature stations, and 
also whenever the appearance of it seems to be different from that taken at the previous sounding. In case of 
doubt, save it always. In general record, in addition to the usual data, at every sounding, all the information 
that can be got without delaying the vessel. Surface densities, however, need not be taken excepting at tem- 
perature stations. Current observations will be made under special orders. Reports will be made to the com- 
manding officer -when circumstances, of whatever nature, would seem to render adherence to any part of the fore- 



24 



DEEP-SEA SOUNDING AND DEEDGING. 



going instnictions impracticable : 
lar relating to the work, and a^ 
operations. 



mexpected, important, or interesting results 
re complete information can be gained eon 



n any particu- 
3ur sj-stem of 



Depth of the sound- 
ing in fathoms. 






Serial depths in fathoms. 


1 


10. 


25. 50. 


75. 


100. 


150. 


200.' 300. 


400. 500.' 600. 


700. 


800. 


900. 


1,000. 


1 


Less than 10 


2 




j 








t 


t 










2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 


10 2 

25 2 

50 2 

75 2 

100 2 

150 2 

200 2 


2 
2 

2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 
2 


































1 ' 2 
1 2 
1 2 
1 2 
1 2 




















.. .. 










2 
2 


1 










1 












2 1 


........ .......... 












2 

9. 














400 


1 212112 
1 2|l|2112 
1 2 12 1 1 2 












500 ' 2 

600 2 

700 2 

800 2 












1 1 \"i' 










1 2 1 2 1 1 2 ' 1 1 2 
1 21 2 1 1 21 12 
1 212 1 1 21 12 

1 212jl 1 2 11 2 


1 

1 
1 
1 








1 
1 
1 






900 

1,000 or more.... 


2 
2 


1 
1 


2 




Sur. 


10. 


25. 50. , 75. 100. 150. 200. 300.: 400. 500. 600. 700. 800.J 900. 


1,000. 


Bot. 



Remarks.— To ascertain the serial depths from which temperatures and specimens of tlie \\-ater are required, iind in the left- 
side column a depth next lower than that of the sounding. Opposite thereto will be found the iigures 1 and 2, the former signifying 
temperatures and the latter both temperatures and specimens, which are to be referred, for the required depths, to the top or bottom 
row of iigures denoting serial deptlis. Thus, in a depth of 250 fathoms, temperatures should be observed at the surface, at 10, 25, 50, 
75, 100, 150, and 200 fathoms, and at the bottom, and water specimens should be secured from the surface, from 10, 50, and 100 fathoms, 
and from the bottom. 

This table was too broad in its application to be strictly followed 
through a whole season, but it indicated in a general way what was 
expected of us, and it served as a guide to the officer of the deck, who, 
in the absence of special orders to the contrary, observed its directions 
without modification. 

From the first, the quality of our work gradually became better. 
There was no year that we did not improve one or more of our appli- 
ances somewhat, and after the first season we trusted the wire to an 
extent not meditated at the outset. 



INTEODUCTION. 25 

OFFICERS OF THE " BLAKE "' AND THEIR CIVILIAN ASSOCIATES. 

Throiigiiout the whole work I was singularly favored in having the 
assistance of intelligent and capable officers, and it is a source of regret 
that their services cannot be presented more prominently in this volume. 
The leading purpose of the volume may, perhaps, explain away any appar- 
ent neglect by me in the matter, when I state that the field of invention or 
adaptation in the party being occupied with so much evident interest by 
myself, the others — some of whom were ingenious in a marked degree — 
kindly accorded me the "right of way." The records of the Coast and 
Geodetic Survey bear testimony to their faithful service and to their high 
qualifications for the work required of them. The names of all the 
officers who have served with me on board the "Blake" will be found in 
the table of statistics accompanying this Introduction. 

My association with Prof. Alexander Agassiz and Mr. S. W. Garman, 
though short, was very pleasant. Professor Agassiz and I were shipmates 
and messmates for but little over two months, during which time we gave 
ourselves up heartily to the work in hand. To these gentlemen belongs 
all the credit, pertaining to the province of the naturalist, which was 
gained on the dredging cruises. 

4 D S 



26 



DEEP-SEA SOUNDING AND DEEDGING. 



STATISTICS OF WOKK DONE BY THE HYDRO 





.^ 




Soundings. 


Watei 


temperatures ob- 
served. 


Water densities ob- 
served. 


Season. 


1 
i 


i. 

2 


1 


1 




Intermedial. 

Bottom. 

Total. 


i ^ 


i 


1 


Winter, 1874-'75. 
Do 


Off mouth of 
Mississippi 
River, Gulf 
of Mexico. 

Gulf of Mexico 

Gulf of Maine. 


219 

2,505 
2,065 


1 
347 

280 134 


347 

414 
664 


348 

378 
664 


132 4 484 

50 223 651 
64 133 861 


369 129 

130 32 
133 64 


4 

125 


502^ 


Summer, 1875... 


649 


15 


330 


Winter,1876-'76. 


Gulf of Mexico 


2,519 


338 


100 


438 


403 


456 91 950 


108 176 


82 


366 


Winter, 1876-'77 do 


6,426 


616 


.. 


1,034 


287 


1,232 273 1,792 


185 350 


137 


672 


- i 

Winter, 1877-'78. Straits of Flor- 
ida, Gulf of 
Mexico. 


1,316 


3 


193 


196 


192 


678 138 1,008 


157 24 


25 


206 


Do ....do 

1 


1,800 


4 


98 


102 


91 


50 141 


(*) (*) (') 


(*) 


Grand total. 


16,850 


2,237 


958 


3,195 


2,363 


2,612 912 5,887 


1,082 775 506 


2,363 


Winter, 1878-'79. Caribbean 
Sea and Pas- 
sages. 







664 


ee. 


670 


547 553 1,770 


437 60 19 

1 


516 



INTRODUCTION. 



27 



GRAPHIC PARTY ON BOARD THE •' BL AKK." 



m 


►5 


^ 


H m 


^^ 


\ "■■ """ f ■■ 


170 


100 


186 


455 211 


20 



127 55 126 308 131 



102 157 79 338 77 ; 68 . 



185 353 183 721 



86 68 Regular party work. 



1 Lieutenant-commander, C. D. Sigsbee ; lieutenants, C. 
I T. HutcMns, J. W. Hagenman, and J. M. Grimes ; 
\ master, R. G. Peck ; ensign, W. E. Sewell ; medical 
I officer, M. L. Crawford, M. D. ; engineer, T. L. 
J Churchill; captain's clerkandrecorder, J.B.Howell. 

. Lieutenant-commander, CD. Sigshee; lieutenants, J. 
E. Pillsbury and W. 0. Sharrer ; masters, R. G. Peck 
and M. F. Wright ; ensign, W. E. Sewell ; assistant 
paymaster, 0. C. Tiffany ; medical officer, M. L. Craw- 
ford, M. D.; engineer, T. L. Churchill; captain's clerk 
and recorder. L. P. Sigsbee. 

. Lieutenant-commander, C. D. Sigsbee ; lieutenants, J. 
E. Pillsbury and W. 0. Shafrer ; masters, R. G. Peck 
andM. F. Wright; ensign, W. E. Sewell; medical offi- 
cer, S.W. McJunkin.M.D.; engineer, T. L. Churchill; 
captain's clerk and recorder, L. P. Sigsbee. 

Lieutenant-commander, C. D. Sigsbee ; lieutenants, J. 
E. Pillsbury (for half the season, then invalided), S. 
M. Ackley (half the season), andW. 0. Sharrer; mas- 
ters, M. F.Wright, W. E. Sewell, and Henry McCrea ; 
passed assistant engineer, W. S. Moore ; medical offi- 
cer, S. W. McJunkin, M. D.; captain's clerk and re- 
corder, L. P. Sigsbee. 

Lieutenant-commander, C. D. Sigsbee ; lieutenants, S. 
M. Ackley and W. 0. Sharrer ; masters, H. M. Jacoby 
and Henry McCrea ; ensign, G. H. Peters ; passed as- 
sistant engineer, W. S. Moore ; assistant surgeon, C. 
J. Nourse ; recorder, L. P. Sigsbee. 



(t) (t) (t) (t) 



617 693 598 1,908 880 224 



40 64 10 



f Commander, J. R. Bartlett ; lieutenants, W. 0. Shar- 

Hauls — rer and J. P. Wallis ; master, H.M. Jacoby ; ensigns, 

[ With dredge-. 71 | G. H. Peters and E. L. Reynolds ; passed assistant 

! With trawl.-- 109 \ engineer, John Pemberton ; assistant surgeon, C. 

1 With tangles .45 J. Nourse ; recorder, L. P. Sigsbee. 

I I For the dredging season: Naturalists, Prof. Alexander 

l^ Total 225 I, Agassiz and Mr. S. W. Garman. 



CHAPTEK II. 

SOUNDING-WIEE, COEEECTION-CUEVE, SOUNDING-EODS AND SINKEES. 

ROPE FOR SOUNDING PURPOSES. 

The principal drawback to deep-sea sounding with rope is the large 
area which rope offers to resistance in its passage through the water, and 
to the action of currents tending to deflect it from a vertical direction. 
This resistance is increased by the rough and grooved surface which all 
ropes have to a greater or less degree. Their weight, if made of hemp or 
manilla, is reduced to about one-fourth in water, and thus there is but 
little weight in the material itself to cause it to sink rapidly. "The 
resistance upon the line varies, first, as the square of the velocity; second, 
as the diameter of the line; third, as the length of line immersed." * 

Since the weight of the sinker remains invariable, and the resistance 
upon the line continually increases as the length of the immersed portion 
becomes greater, it follows that the rate of paying out will gradually 
lessen and must become very slow if the whole resistance approximate to 
the weight of the sinker. With the weights and ropes formerly used it 
came about, in deep casts, that the resistance of the line would so nearly 
equal the weight of the sinker that, before bottom had been reached, the 
line would be sinking almost wholly by its own weight, and the rate of 
paying out after bottom had been reached would, therefore, remain about 
the same as for some time- previously, giving no indication of the time 
when the sinker had landed. The invention by Brooke, permitting the 
sinker to be detached on striking bottom, made it practicable to use much 
heavier weights than it would be possible to haul back with any rope 
suitable for sounding purposes. Since then the use of small line with 
very heavy sinkers, and the taking of time-intervals when paying out, have 
made rope soundings acceptable in general, yet, in strong currents the 
most experienced and accomplished hydrographers have been known to fail 

* Appendix No. 37, Coast Survey Eeport for 1858. Investigation of the laws of motion governing the 
descent of the weight and line in deep-sea soundings ; by Prof. W. P. Trowbridge, Assistant in the Coast 
Survey. 



SOXnSTDrnG-WIEE, COREECTION-CUEYE, ETC. 29 

completely in its use, and attempts in heavy seas would probably prove 
ineffectual also. The latest and most trustworthy deep-sea soundings 
with rope have been taken with stuff from 0.8 inch to 1 inch in circum- 
ference (0.25o-inch to 0.318-incli diameter), the sinker weighing one 
hundred pounds for a depth of 1,000 fathoms, with one hundred pounds 
added for each additional 1,000 fathoms of anticipated depth. 

WIRE FOR SOUNDING PURPOSES. 

Attempts were made to sound with wire from time to time, but there 
was no encouraging measure of success until 1872, when Sir William 
Thomson invented a machine for the purpose. With machines con- 
structed on his principle we are now able to make the deepest cast with a 
percentage of probable error as small as pertains to ordinary in-shore 
soundings with the hand-lead. His original apparatus has since been 
improved by himself and by others, but not in point of accuracy, this hav- 
ing been attained by Sir William Thomson in his first efforts in sounding 
with wire. The kind of wire that he originally recommended was adopted 
on board the "Blake," and, so far as I am aware, no other is employed 
for sounding purposes. A piece may be seen pictured on Plate 2, where 
it is contrasted with a rope of one-quarter of an inch diameter to which 
the thermometer case is attached. 



oo 



Fig. 1. Fig. 2. Fig. 3. 

A.— Comparative size of hemp rope and steel wire for sounding purposes. 

Figs. 1 and 2. Hemp sounding-line. Fig. 3. Piano-forte sounding-wire. 

DESCRIPTION OF PIANO-FORTE WIRE USED FOR SOUNDING PURPOSES. 

The material used is steel piano-forte wire of No. 22 Birmingham 
(Stubbs) gauge, which corresponds nearly to No. 21 American wire-gauge 
(0.028 of an inch in diameter) ; it weighs fourteen and one-half pounds to 
the nautical mile (1,000 fathoms approximately) in air, and consequently 
about twelve pounds in water. We purchased ours either of Messrs. Web- 
ster & Horsfall, Birmingham, England, or of the Washburn & Moen Man- 
ufacturing Company, of Worcester, Mass. The English wire has a tensile 
strength from two hundred to two hundred and forty pounds, and costs 



30 BEEP-SEA SOUNDING AND DEEDGING. 

about seventy-five cents per pound.* It is provided in lengths from one 
hundred fathoms to four hundred fathoms, and is made up in eighteen-inch 
coils, weighing about sixty pounds each, and wrapped with oiled paper. 
The American wire, which is called music-wire No. 13 by the Washburn 
& Moen Manufacturing Company, has a tensile strength somewhat less than 
that of the English wire, and costs about $1.50 per pound. It seems to 
have a higher polish than the English wire, and is made up in nine or ten 
inch coils, stowed neatly within sealed tin cases. The method of pro- 
tecting the English wire for transportation is not a good one, for it is often 
found that a piece of the paper has become stripped off by careless hand- 
ling, leaving many layers of the metal exposed; but this is a matter which 
would doubtless receive attention if brought to the notice of the manufac- 
turers. M. Poehlman, of Nuremburg, Germany, exhibited some of his 
piano-forte wire at the Centennial Exhibition, which wire, by the official test, 
proved to possess a strength of about ten per cent, over the English wire on 
exhibition; but Messrs. Webster & Horsfall may not have been exhibitors. 

METHODS OF SPLICING THE WIRE. • 

Splicing seems to have given Sir William Thomson considerable 
trouble in his first experiments, for the reason that an abrupt change of 
section from a thick splice to the single part of wire made a point of weak- 
ness, and in his earlier tests the wire always broke just at the splice. He 
finally settled on a method described by him as follows : 

"A splice of two feet long I have found quite sufficient, but three feet may be safer. The two pieces 
of wire are first prepared by warming them slightly and melting on a coating of marine glue to pro- 
mote surface friction. About three feet of the ends so prepared are laid together and held between the finger 
and thumb at the middle of the portions thus overlapping. Then the free foot and a half of wire on one 
side is bent close around the other in a long spiral, with a lay of about one turn per inch, and the same is 
done for the free foot and a half on the other side. The ends are then served round firmly with twine, and 
the splice is complete." 

In connection with the above I give one of Haswelfs recipes for ma- 
rine glue, although the mixture is probably a commercial article : 

"Dissolve india-rubber, 4 parts, into 34 parts of coal-tar naphtha; add powdered shellac, 64 parts. While 
the mixture is hot it is poured upon metallic plates in sheets. When required for use it is heated and then 
applied with a brush." 



* Three lengths of English wire were recently tested on board the "Blake" and broke at the following 
IS : 204, 210, and 202 pounds. Occasionally a piece will break at a strain less than 200 pounds. 



U. S. COAST SURVEY. 



Plate 2. 

DEEP-SEA SOUNDING AND DREDGING. 





FIG. I. FIG. 2. 

FIG. I. MILLER-CA3ELLA THERMOMETER CASE FITTED WITH SIGSBEE'S SPRING CLAMP.j ABOVE IS 

SHOWN A PIECE OF THE SOUNDING WIRE. 
FIG. 2. SOUNDING ROD ; A SLIGHT MODIFICATION OF CAPTAIN BELKNAP'S SOUNDING CYLINDER NO. 2, 
WITH SIGSBEE 3 DETACHER. THE CONSTRUCTION IS SHOWN ON PLATE 39. 



ffeliotype Pri, 



■e St., . 



SOUNDING-WIRE, COEEECTION-CURVE, ETC. 31 

The New York Rubber Belting Company advertise "pure rubber 
cement/" which is pure rubber gum dissolved in naphtha. 

Gapt. George E. Belknap, U. S. N., Avho has taken the deepest casts 
ever made, explains his splices in this manner: 

"Long-jawed twist two feet in length; soldered ;it ends and two or three places in middle, and served 
with fine waxed twine.'' 

All anxiety about our splices on board the '"' Blake" was saved us by 
Commander Howell. The kind that he had used in his initiatory sound- 
ings from the "Blake" was found to answer perfectly. Experience shows 
that with these the wire rarely, if ever, breaks at the point where the 
single part joins the splice. While we have not sounded in the deepest 
water, we have nevertheless many times, when reeling in by steam, sub- 
jected these splices to as much strain as would be brought upon them in 
the deepest cast ever taken; in fact, Ave have parted the Avire a number of 
times by direct strain through one cause or another. While, from the 
shape of the splice, it is probable that the theoretical point of Aveakness 
is retained in a small degree, yet it may be presumed that in every great 
length of wire there Avill be other comparatively weak spots, removed from 
the splices, Avhich Avould not sustain so strong a pull as the points in ques- 
tion. We ahvays regarded our splices as entirely satisfactory, and they 
appear to have decided advantages over those heretofore described, the 
chief of Avhich are that they need less attention and repair and are less 
liable to get stripped; they are but three inches long, AA^hich makes them 
stoAv compactly upon the reel; are neat and smooth; are easily made and 
reneAved, and need not be served Avith twine or other material. They are 
shoAvn on Plate 41. In making them caution should be observed not to give 
the lay at the cross or middle of the splice so short a nip that it Avill after- 
Avards be straightened out under strong tension. The form shoAvn on the 
plate is correct. In soldering, the ends should be given as long a taper as 
quick soldering Avill alloAV, for it Avill not do to keep the hot iron very long 
on the single part of the wire for fear of altering the temper of the steel. 
We were in the habit of having them made ahvays by the same machinist, 
on the principle that ''practice makes perfect," but almost any person Avho 
is handy Avitli tools could make them Avell enough. Their shape is so reg- 



32 DEEP-SEA SOUNDING AND DREDGING. 

ular that a simple machine might be devised to make the twist. The outfit 
necessary for making splices consists'of the following: a small charcoal 
stove, such as is used by tinsmiths, two soldering-irons, some soft-solder, 
nippers, plyers, and a bottle of spldering-fluid. For the last mentioned, 
Haswell gives this recipe, which is the same, or nearly the same, as that by 
which we made our soldering-fluid : 

"To two fluid ounces of muriatic acid add small pieces of zinc until bubbles cease to rise; add one-half 
teaspoonful of sal ammoniac and two fluid ounces of water." 

For the purnose in view this fluid is more useful than resin, because 
more searching. It should be applied sparingly with a feather or a brush, 
immediately before the soldering-iron is used.* 

PRESERVATION OF THE WmE WHEN NOT IN USE. 

When wire was received in sealed tin cans the latter were painted and 
stowed below in a dry place, after which only an occasional inspection or 
touching up of the outside of the cans was necessary. When it was sup- 
plied to us in coils wrapped with oiled paper we would parcel each coil 
with soft canvas, and then apply several coats of paint before stowing 
them below. Once when we wished to stow away a spare reel containing 
several thousand fathoms of wire, and had no tank available, we left the coil 
upon the reel, covered the upper layers with old washed flannel saturated 
with sperm-oil, spread tallow over the flannel to a depth of half an inch, 

* I have noticed in one of the late reports from the United States Steamer "Tuscarora," Commander J. 
W. Philip, regarding the work of that vessel, that they had been unfortunate with some splices made after 
the •■'Blake's" method. The wire used had been received frotn the United States Steamer "Alaska," where it 
had been in service. On board the "Alaska" was Master W. E. Sewell, formei-ly of the "Blake," a most 
efficient worker witli sounding-wire, and one who knew perfectly the "Blake's" method of splicing. I have 
no knowledge of the length of time that these splices were used by the "Alaska;" how long they were in 
stowage thereafter; in what fluid they were stowed, or if they were examined and repaired preparatory to 
use by the "Tuscarora." I imagine, however, that they were not repaired, as our naval vessels are not usually 
given more than one reel, and have, therefore, no facilities for winding off' wire for examination. 

Later, the United States Ship "Saratoga," sailhig training-ship, Commander E. D. Evans, has used our 
splices with entire satisfaction. Lieut. W. M. Wood, who had charge of the sounding-machine, practiced such 
a neat way of applying the solder, in order to avoid burning the wire with the soldering-iron, that I give his 
method here : Across a strip of board, about six inches wide, a narrow score or groove was made, which was 
deepened in the middle for a length somewhat greater than that of the splice. With the hot iron the solder was 
melted so as to fill the deep part of the score. The splice was then run backwards and forwards through the melted 
solder, lengthwise in the score, until the soldering was complete. Afterwards the roughness was smoothed down 
with a knife. I cannot help thinking, after my experience with them, that these splices are sufficiently strong, 
and in every otlier respect they have the advantage over the other splices. 



SOUNDIITG-WIEE, COKEECTION-CURVE, ETC. 83 

and then wrapped the whole reel in old canvas and stowed it below in a 
cool place. Our methods in this respect answered the purpose for which 
they were intended. 

WINDING OFF WIRE FOR USE OR TRANSFER. 

Plate 41 shows our method of mounting the coils for winding upon the 
sounding-reel; the second reel — that nearest the turn-table — being unnec- 
essary after the correction-curve, shortly to be described, has once been 
obtained. The turn-table may be made of a circular disk of wood, perfo- 
rated with auger-holes, arranged in radial lines and on concentric circles, 
into which pegs may be inserted to suit the coil ; the disk being centered and 
mounted upon any stable pedestal or standard, the apparatus is complete. 

When wire is passed from one reel to another a slight resistance 
should be placed upon the losing-reel — by securing the friction-line by 
one end and laying it loosely over the friction-score of the reel — in order 
to keep the wire taut and thus avoid kinking. A friction-score may be 
turned around the turn-table disk for the same purpose. 

To take wire from a sounding-reel, where it has been in use, and 
make it up again in close coils is not easily done. The difficulty lies in 
getting an equal strain on each convolution : failing in this, the coil may 
spring into a figure-of-eight shape when released from support, particu- 
larly if the coil be not made as nearly as possible of the same size as 
when wrapped upon the reel. Before being removed, if wound on a turn- 
table, the coil may be lashed to transverse strips of wood or iron should a 
tendency to twist be noticed. 

STOWAGE AND SUPPLY OF WIRE: A SUGGESTION. 

A simple method of stowage and supply of wire would be to transfer 
the commercial coils, as soon as they are received, to special cast-iron 
reels or drums capable of holding four or five times as much as the ordi- 
nary sounding-reels. In winding the wire to the supply-drums the splices 
might be completed at once, which would give the advantage of always 
having the supply in very long lengths, from which losses could be quickly 
replaced at sea or in port. These drums, when wound with wire, might 
be kept in tanks of oil or lime-water. 



34 DEEP-SEA SOUNDING AND DEEDGING. 

Something like the following would perhaps suffice for merely con- 
taining and transferring wire. A cheap cast-iron drum, one foot in diam- 
eter and two and a half inches wide inside the flanges, with side flanges 
nine inches deep and friction-score at the side; center bored for the re- 
ception of an axle of a sounding-reel for mounting on standards. Such 
a drum would hold more than 20,000 fathoms of wire of No. 22 Birming- 
ham gauge, wound with ordinary care. The register on the gaining-reel 
w^ould give the measure of the wire reeled off and that remaining on the 
supply-drum, if used in connection with the correction-curve. 

The winding of wire from a turn-table is a slow operation and can 
best be done in port. 

GUIDING THE WIRE IN REELING UP AND UNREELING. 

The even winding of the wire, which would, at first, seem to present 
difficulties, in reality gives little -or no trouble under careful management. 
Accurate guiding is necessary, but this may easily and successfully be 
done. If ridges are allowed to form when reeling up, in the subsequent 
operation of paying out they will slip and loosen some of the turns, which 
is certain to bring about kinking if the paying out be continued. 

This mishap came to us but once, and then when we had more than a 
thousand fathoms of wire in the water. The annoyance and delay that it 
caused made us guard carefully against a recurrence of similar accidents. 
Neither swabs nor soft rags should be used for guiding, as they catch in 
the splices when least expected. The best thing for the purpose, accord- 
ing to our experience, is a piece of stiff canvas folded several times; the 
rounded fold being pressed against the wire with both hands. This can 
be managed by one man; is adapted to any change of direction that the 
wire may take; is always available, and presents a smooth surface, which, 
if chafed, may be quickly renewed by refolding the canvas. 

PRESERVATION OF THE WIRE IN USE I THE TANK. 

The preservation of the wire when on the working-reel is an impor- 
tant point, but presents no serious obstacle to the use of wire for sounding. 
Thatw^e should have been able to keep the same length in use for a year is 



SOUNDING- WIRE, COREECTION-OUEVE, ETC. 35 

proof of this. When not on our lines the sounding-reel and its wire were 
kept in a cylindrical tank of galvanized sheet-iron, containing sperm-oil. 
The tank is built up inside, so that, as nearly as possible, there is but a film 
of oil beneath and at the sides of the reel, while on top it is covered to a 
depth of about one or two inches. The cover is a flat, circular piece of 
sheet-iron, riveted all around its edge to the under side of a wrought-iron 
ring, the latter being perforated to receive screws projecting at regular 
intervals through a second wrought-iron ring or flange fastened around the 
inside of the top edge of the tank. In the center of the cover is a square 
hole, through which the axle of the reel is allowed to project. A sheet- 
iron, cylindrical, water-tight cap, to fit over this hole, is a desideratum. It 
should be about six inches in diameter and four inches high, so as to cover 
the stray-line, which, being connected with the wire, is rove up through 
the central hole and coiled down upon the tank when the reel is stowed.* 

The cover of the tank, when in place, is set up firm by means of 
thumb-screws, and between the two wrought-iron rings, already mentioned, 
which form the joint, a washer of rubber or sennit is interposed to prevent 
leakage of the oil in a sea-way. In the foreground of Plate 7 the top of 
the tank is shown, covered with a canvas hood. 

Sir William Thomson at first suggested that the wire be kept in a solu- 
tion of caustic soda when not in actual use. This mixture being found by 
Captain Belknap to slightly affect the solder of his splices, that officer sub- 
stituted sperm-oil in its stead. Since then Sir William Thomson has ad- 
vised that lime-water be used in the tank, and kept up to full strength by 
occasionally dropping in a lump of burnt lime. Lime-water is certainly 
recommended by its cheapness, and would probably answer well to preserve 
the wire in the tank, but sperm-oil, although expensive, has been shown by 
long experience with it to be a thoroughly trustworthy preservative. For 
preserving the working wire, when the reel was mounted for use, we always 
had in store a few cans of concentrated lye, such as may be bought at 
any ship-chandlery. From this stuff we made an alkaline mixture, which 
was kept near the sounding-machine in an iron bucket. We never used 

* The stray-line is a piece of small rope, from 10 to 15 fathoms in length, connecting the sinker or souud- 
ing-rod with the outer end of the wire. It will be described in the next clia})tef. 



36 DEEP-SEA SOUNDING AND DEEDGING. 

drip-pans, thinking them cumbersome. The alkaline water was frequently 
but sparingly applied to the wire on the reel, in winding or unwinding, by 
means of a swab fitted with a wooden handle. If used too freely it flies 
into the faces of the men working at the machine, causing much annoyance. 
When the wire had been long exposed, and was noticed to have taken on a 
rusty color, the surface-layers were scrubbed with lye-water, then rinsed 
with fresh water and oiled. , It is a good practice to perform the same 
operation when the sinker has reached bottom and a stoppage is made to 
let the bottom thermometer register. Before a reel is stowed in sperm- 
• oil it should be carefully scrubbed and washed with fresh water to avoid 
fouling and thickening the oil. A litmus-paper test would show at any 
time if the oil were getting acid from any cause, and oil should be tested 
before it is purchased. 

KINKING. 

Chief in importance of all things to be guarded against when sounding 
with wire is ^^ kinking.'''' By the emphasis which I attach to kinking, I do 
not mean to imply that it is necessarily an accompaniment of sounding with 
wire, or that there is a frequent appearance of parts or spots showing a 
tendency to kink and demanding special presence of mind in the person 
having charge of the machine. On the contrary, I think a kink is less 
likely to happen in the wire than undue chafe in a sounding-rope, but there 
is this difference : a rope may sustain considerable chafe and yet be in no 
immediate danger of parting in ordinary work, while if the wire kink it is 
almost certain to break under a light strain.* In no case should even an 
incipient kink be trusted. By not losing sight of the qualities of the wire 
in connection with the character of the sounding-machine, the watch-officers 
of the "Blake" would not for months together, or even for a whole season 
or more, encounter a single kink. As long as the wire is taut it is saf&; 
but if allowed to slack it will have a tendency to assume the shape of the 
convolution in which it has been wrapped under strong tension, either 
upon the reel or in the coil. From this tendency we have bights or loops, 
which, if not cleared by hand, form kinks when the wire is again subjected 
to tension. 



Bnt testis of tlie strength of English wire iu kinkSj the wire parted at the following strains, each 
: 46, 54, 46 pounds. 



SOUNDING-WIEE, COBEECTION-CURVE, ETC. 37 

WIRE TESTS AND WORKING STRAIN. 

Several pieces of the working wire should be tested for strengih from 
time to time, with a view of finding the limit of strain which it would be 
safe to put upon it. I would suggest, as a safe rule for beginners, that the 
wire be worked to no more than one-half its breaking strain. With us dis- 
carded wire was kept upon a spare reel, to be used for the outer lengths 
in case the better material should give out. Such stuff might be made 
up into coils, each coil being tallied with a record of its length, tensile 
strength, and history, when it could be made to serve for make-shifts. 
When wire which has lost much in uniformity of strength is used with the • 
sounding-machine, it is prudent to keep a memorandum of the working 
strain of each length, that the person who superintends the working of the 
machine may be able to exercise a correct judgment when reeling in. The 
risk of losing rods, water-cups, and thermometers is too great with weak 
wire, however, to sanction the use of any but the best material if it can 
be had. 

THE CORRECTION-CURVE. 

All deep-sea sounding-reels that I have seen are of such a size that 
their drums will exactly accommodate one fathom of the sounding-wire 
as a single turn (Plate 17 and others). While each turn of the first layer 
wound about one of them is, therefore, one fathom in length, those that 
are above measure more, according to their distance from the drum. Each 
reel is rigidly attached to an axle, on which is a worm to connect with 
the train of a register for recording the number of revolutions of the reel 
(Plates 36-38). It is evident that the readings of the register show^ the 
number of turns of wire paid out or reeled in, but not the number of 
fathoms, and, since the turns are almost constantly varying in length, it 
becomes necessary to have some ready means of reducing them to fathoms 
in order to arrive at the depth of the sounding. For this purpose the 
correction-curve (Plate 41) was devised on board the "Blake" at the com- 
mencement of our first season, and its use was continued thereafter 
throughout Lhe whole four years of our work. 

To get the data for constructing a correction-curve like that on Plate 
41, the commercial coil of wire is mounted upon a turn-table and two 



38 DEEP-SEA SOUNDING AND DEEDGING. 

empty reels are placed as shown on the plate. The wire is led from the coil 
five or six times around the first, or spare reel, and the end is secured to the 
drum of the second, or working reel. Then, as it winds in accumulating 
turns on the working reel, it only passes on and off the spare reel in non- 
riding terms of one fathom each. A register being applied to each axle, 
that placed on the working reel will record turns as they occur in actual 
sounding, while that on the spare, or measuring reel, will give the corres- 
ponding/«^;/^oms. From this it follows that, at any stage of the transfer, the 
difference between their readings is a correction which, if added to the read- 
. ing of the register connected with the axle of the working reel, will give 
the number of fathoms of wire reeled off. As the operation progresses a 
table is prepared like that on Plate 41, from which the curve may be con- 
structed in a few minutes. 

I have known misapprehension to exist in the minds of a few persons 
who have given this curve only a hasty notice. Some have understood 
that we used a spare reel at every sounding to measure the length of wire 
paid out; others have thought that each vessel would require a curve 
at the outset, and a new one whenever wire was added to the working 
reel or lost from it thereafter. I will attempt to make it clear by stating 
that only the working reel is used at soundings ; the spare one serves 
the sole purpose of getting the data, so far as any connection with the 
curve or the other reel is concerned. A curve once obtained is always 
applicable to the same kind of reel and wire that was used to get it, and 
this without regard to losses or gains of. wire within the limit of the 
extension of the curve ; for example, if made out for only 3,000 turns 
the curve will not suffice for 4,000 turns, but if carried forward in the 
first instance to include the figures of the greatest possible depth of 
water, there will then be no limit to its use with the original size of reel 
and gauge of wire. From this it will be seen that if all the sounding- 
reels, supplied from any source, be made with drums of equal dimen- 
sions, and the same gauge of wire be used with all, then the parties 
issuing the reels, by constructing a curve in a single instance, and ex- 
tending it for the total amount of wire that a reel is capable of contain- 
ing, may provide a photolithograph, engraving, or other copy of the 



SOUNDING-WIKE, COEREOTION-CUEVE, ETC. 39 

original curve with each machine as part of its outfit, in which case no 
future measurements nor preparation of tables will be necessary with 
those machines. 

It has been stated that winding the wire smoothly is a simple matter 
and need not be classed amongst the difficulties. In reeling back, after a 
sounding, the index of the register nearly always returns to precisely the 
same point whence it started, and I have never known, even in depths as 
great as 2,000 fathoms, a discrepancy amounting to as much as three turns. 
Should any considerable difference occur, and should equal dependence 
be placed in the register record of paying out and that of reeling in, then 
a correction may be found for a mean of the two readings of the register. 
If wire be lost from the reel or added to it, a new constant, c, correspond- 
ing to the altered number of turns, t, in actual use, must be sought, and 
the rule applied just as before. The "Blake's" curve, framed and hung 
in the pilot-house, was always at hand, and to effect a reduction after a 
sounding was the work of but a few seconds. 

In the Sigsbee sounding-machines (Plates 7 and 8), the wire after 
leaving the reel passes over a pulley above, which is one yard in circum- 
ference less the allowance for the thickness of the wire. An odometer 
(Plate 38). was at first attached to the axle of this pulley, and by its read- 
ing showed at once the number of yards of wire paid out at a sounding. 
We could, therefore, work independently of the correction-curve or of any 
other measurement than that of the pulley, but the position and size of 
the register on the axle of the reel was so convenient that we preferred 
the use of the register. We found the two measuring-instruments to agree 
after the usual correction, it being necessary in each case to make a small 
allowance for the four or five revolutions that the pulley always gave after 
bottom had been reached. 

SOUNDING-RODS. 

An instrument made fast to the outer end of a sounding wire or rope, 
and which, being inserted within the sinker and projecting through it, 
serves to retain the sinker in the descent and to detach it when bottom 
has been reached, is usually called a sounding-rod. 



40 DEEP-SEA SOUNDING AND DEEDGING. 

A single rod is sometimes made to perform three separate ofTiceS; viz, 
to bear the sinker to the bottom and leave it there ; to bring up a speci- 
men of the bottom soil; and to bring up a specimen of the bottom water. 

There are objections to the employment of a sounding-rod for bring- 
ing up water-specimens. To adapt them to this purpose involves the ap- 
plication of an arrangement of valves, more or less expensive, and, since 
bottom water is not wanted at every sounding on a connected line such 
as ours were, it does not seem economical to risk costly accessories unless 
something is to be gained. In regard to this, only a certain number of 
rods in any outfit might be supplied with valves, the others being without 
them; but there is a more weighty objection than that mentioned above. 

It is doubtful if a genuine bottom-water specimen is always secured 
by means of a combined rod and water-cup when the rod has returned 
from soft bottom; for, owing to mud entering and fouling the valves and 
their seats, or from a deposit upon these parts of particles held in temporary 
suspense on account of the agitation caused by the impact of the sinker, 
the valves may not seat perfectly at the moment of beginning to haul 
back. This contingency should be all the more carefully guarded against, 
because, during the ascent, the reverse current of water through the rod, 
allowed by the non-seating of the valves, would probably clear away the 
obstructions, and thus the rod might come to the surface with every ap- 
pearance of having worked well, when in reality the specimen of water 
within would be of no value whatever. 

On board the "Blake," when we wanted bottom water, a water-cup 
was used and fastened two or three fathoms, according to depth, above 
the sinker or rod. The water-cups will be described hereafter. 

During our first three years we used the rod known as Capt. George 
E. Belknap's sounding-cylinder No. 3, with the difference that the Sigsbee 
detacher was added in place of the single hook, and that a device was 
applied to overcome the objections to a flat-headed cylinder for use with 
sinkers fitted with iron bails or slings, of which more will be said here- 
after.* 

* For description and drawing of the original cylinder No. 3, see " Deep-sea soundings in the Pacific 
Ocean, obtained in the United States Steamer 'Tuscarora' by Commander George E. Belknap, U. S. N." 
U. S. Hydrographic Office Publication, No. 54. 



U, S. COAST SURVEY. 



Plate 3. 

DEEP-SEA SOUNDING AND DREDGING. 





MILLER-CASLELA THERMOMETER CASE FITTED WITH SIGSBEE'S SPRING CLAMP. 
SOUNDING ROD; A SLIGHT MODIFICATION OF CAPTAIN BELKNAP'S SOUNDING CYLINDER NO. 2 
WITH SIGSBEE'S DETACHER. THE CONSTRUCTION IS SHOWN ON PLATE 39. 

Heliotype Printing Co., 220 Devonshire St., Boston. 



SOUNDING-WIEE CORRECTI05T-OITEYE, ETC. 41 

In this rod the arrangement for getting a bottom-soil specimen con- 
sisted of an auger-shaped spindle terminating in a conoidal cup. A 
cylinder which was kept above the auger in the descent fell down and 
inclosed it on detaching the sinker. This did remarkably well for bring- 
ing a specimen from soft bottoms, which was all that Captain Belknap 
claimed for it, but as our expectation for finding sand, shells, or coral 
increased, something different appeared to be necessary. 

It is not always possible to foretell the consistency of bottom-soil 
specimens, and when, therefore, it is surmised that it will be varied over 
the locality to be sounded, a rod should be used which will probably give 
at least slight evidence of any bottom composed of fine loose material. 
In order to determine on some good shape for a specimen-cup — that part 
of the rod which gets the specimen — I supplemented my experience by 
experimenting with a number of devices in wet sand, which is one of the 
most difficult of bottom materials to bring up with a sounding-rod.* 

The result of my experiments showed that a simple cylindrical pipe, 
open at both ends, could be plunged far into the sand, which, however, 
resisted the blunter forms to a degree that precluded their adoption. 
Here was a suggestion — to shape the specimen-cup as nearly as possible 
like an open cylindrical pipe ; to drive it into the bottom material, and to 
retain the inclosed specimen. Captain Belknap's sounding-cylinder No. 2 
seemed to answer the demands better than anything else, the poppet-valve 
being, to my mind, preferable to the butterfly-valve which is sometimes 
used. Accordingly, cylinder No. 2 was modified by me in some respects, 
and fitted with the Sigsbee detacher, after which it was brought into ser- 
vice on board the ''Blake" (Plates 2 and 3). The spring, the cone top, 
and the fittings for permitting the escape of water are changed somewhat 
from Captain Belknap's plan, but their operation is, in effect, about the 
same. It is not intended that this rod shall get a specimen of the bottom 
water. 

* I have sometimes seen repeated trials with a fifty-pound lead, armed with a Stellwagen cup (Plate 5)) 
fail to get a single grain of material from bottom known to be only of sand, the depth being only four or five 
fathoms. 

6 D S 



42 DEEP-SEA SOUNDING AND DEEDGING. 



description of the modified belknap s sounding-cylinder no. 2, fitted with 
sigsbee's detacher. 

(Plate 39.) 

The cylinder A (Figs. I, II. III. and VI). with a screw-joint at B 
(Figs. I, III). 

A casting, composed of the upper and lower cylindrical guide-stems 
G, G (Figs. I, III, IV, V, VI) and the perforated plate J (Figs. I, V, VI), 
rigidly attached to the upper part of the cylinder A. 

The valve-seat E (Fig. I). 

The poppet-valve F (Figs. I, II, and III), rigidly connected with the 
pipe G (Fig. I) which travels loosely on the lower guide-stem G (Fig. I). 

The weak spiral spring H (Fig. I). 

The hollow cone I (Figs. I, II, III, IV, VI), to the bottom of which is 
soldered the smooth cylindrical ring D (Figs. I, V, VI). 

The apertures P, P, &c., for the escape of water (Figs. I, II, III, V. 
and VI). 

A detacher composed of the swivel K, the pawl L, the tumbler M; 
and the spring N, of No. 14 American gauge — or No. 15 Stubbs's gauge — 
sjjring-bmss wire (Figs. I, II, III, IV). Every part of the rod and detacher 
is of brass.* 

In connection with the above is used the iron shot-sinker Q, fitted 
with the iron-wire bail R (Figs. I, II). 

WORKING OF THE SOUNDING-ROD. 

(Plate 39.) 
During the descent, the cone I is kept up by the shot as shown in 
Figs. I and II (see also Plate 2), and on striking bottom the bail is pre- 
vented from getting over the top of the detacher by the bearing which the 
shot has under the cone. 

* The idea of leaving the sinker on bottom in deep casts was first put in acceptable mechanical shape 
by Passed Midshipman John M. Brooke, U. S. N., now Professor Brooke, of the Virginia Military Institute. 
Tlie leading feature of his device was a rotating hook. Since writing the above it has been claimed for him 
tliHt my detacher is a modification of his, a point which I willingly concede. Although in designing my form of 
detacher I had no tliought of modifying that of Brooke, yet, had I not been familiar with the latter, the peculiar 



SOUNDING-WIRE, CORREOTION-OURVE, ETC. 



18 



On reaching bottom the slacking of the wire — or, more strictly, its 
diminished tension — allows the tumbler of the detacher to trip, and the 
shot is then free to slide off the cylinder. The tumbler is kept back by 
the spring wire N, and cannot rehook the bail. Fig. Ill (see also Plate 3). 
The resistance of the bottom material raises the poppet-valve, thus allow- 
ing the specimen to pass into the cylinder, a free escape of the water from 



J sounding-rod — as I liave defined 



sliape of the former might not have suggested itself to me. In fact, there is : 
the term — that is not a modification of Brooke's rod in one respect or another 

I give here a wood-cut of Brool^e's apparatus. By com- 
paring the cut with Plate 39 the extent of my modification may 
be seen, while the explanation on this page will show how 
carefully the form of the Brooke detacher was studied by the 
inventor in order to adapt it to the requirements of sounding 
with rope. The explanation is taken almost verbatim from a 
pamphlet published by the Bureau of Navigation, Navy Depart- 
ment, in 1868, entitled "General Instructions for Hydrographic 
Surveyors," &c. 

"A is a shot, cast with a hole through it, and slight 
grooves on its sides to receive and steady the slings. B is a rod 
to which is attached an arm, C, moving vertically about the pin 
D, and from which the shot A is suspended by slings. The lower 
end of the rod B is tubular, receiving the barrels of several goose- 
quills open at both ends, with the cut downward, retaining their 
places by their elasticity. At the top of the tube is a valve of 
thin leather opening outward; it permits the water to fiow through 
the quills as the rod descends, but. closing as it is drawn up, pre- 
serves the specimens intact. 

"The proportions of this instrument are such that when 
the shot is suspended from the arm C, the point of contact x, 
the point of suspension y, and the point of resistance Z, all lie ^ 
in the same vertical line ; the weight of the rod B will then give 
the arm C a slight inclination, which, with the friction of the 
water on the line holding it back, guards against premature 
detachment. 

"It is obvious that the sensitiveness of this detaching 
apparatus will depend upon the relative position of these three 
points; for the arm C may be regarded as a lever of the second 
order with its fulcrum at D ; the gravity of the shot as the power 
acting upon the resistance of the line. So that by increasing or 
diminishing the distance of the ring H from the pin D the detach- 
ment is rendered more or less difficult. In order that change of 
position in the arm C, as it yields to the pull of the shot in the 
act of detaching, may not interfere, it is so made as to permit the 
ring to slip back as the arm inclines." 

This detacher, I think, would be too sensitive for use with wire. I purposely gave mine a form to insure 
against premature detachment and to permit the rod to penetrate well into soft-bottom material. Commander 
Bartlett reports that in the 250 casts taken by him with shot, using the Sigsbee detacher, there was not a single 
failure 




-BkOOKE'.S SorNDING-ROD A 

Detacher. 



44 



DEEP-SEA SOUNDING AND DEEDGING. 



the latter being provided for by the apertures P, P, &c.* On hauUng 
back, the valve drops to its seat, or is forced back by the spiral spring H, 
and the cone falls, closing the upper apertures against a current of water 
through the cup. When the rod is recovered the specimen-cup may be 
unscrewed for extracting the bottom material (Plate 3) .f 



* Experiment has shown of late that it would be a 

m 




C. — Belknap Sounding-cylinoer No. 2. 



1 improvement to do away with the stud which projects 
from the lower part of the poppet-valve, leaving the 
under surface of the valve smooth. 

1 1 give herewith a wood-cut showing, in sec- 
tion, the original cylinder No. 2 by Captain Belknap. 
Although the use of a poppet-valve in a specimen-cup 
is not original with Captain Belknap, my intention 
was directly to modify his cylinder. The description 
already given of the modified rod will suffice to explain 
the original. I had at first only referred to a publica- 
tion wherein a drawing of the original No. 2 might be 
found, but since Captain Belknap has stated that he 
does not think my changes improvements, it seems 
due to him that his cylinder should be given a graphic 
representation on these pages. It is also proper that 
the alterations should stand or fall according to their 
merit. 

The changes made by me in the rod proper 
or cylinder are, briefly, as follows : Substituting a 
cone top for that shown in the wood-cut ; dispensing 
with the inside water- valve; enlarging the specimen- 
aperture and poppet-valve ; giving the bottom of the 
cup a sharper bevel ; employing a spring of greater 
diameter in order to get more elastic movement; 
making provision for the escape of water at the 
moment of impact. 

In the oi'iginal there is no escape for water from 
the small cylindrical chamber in which the stem of 
the poppet-valve is guided, excepting what may take 
place around the valve-stem. In deep water, owing 
to pressure, the valve-stem has above it, in its cham- 
ber, a practically incompressible column of water and 
a highly compressed column of air resisting the lift- 
ing of the valve; hence an escape must be provided. 
This may be done by perforating the guide-cylinder, 
or by slightly filing away a side of the valve-stem; 
but I have changed the form of the apparatus consid- 
erably in this respect, chiefly to get a more effective 
spring. 

The testimony of records is in favor of the 
modified rod, but with the wood-cut available it 
would be easy to construct either rod that might be 
preferred. 



SOUNDING-WIRE, CORRECTION-CUE VE, ETC. 45 

NOTES ON THE CONSTRUCTION OF THE SOUNDING-ROD. 

(Plate 39.) 

The Sigsbee detacher was used by us for nearly all soundings in 
which the sinker was left on bottom, the few exceptions occurring during 
the early part of our first season and in experimental trials with other 
devices. It was so highly appreciated by the officers who used it that 
most of them would appeal from instructions to use any other. When 
properly made it is, perhaps, as little liable to fail as an ordinary pedes- 
trian is to stumble, but the drawing should be followed strictly in the 
construction. The following points should receive attention in the man- 
ufacture of the detacher and cylinder: 

I. The pawl and tumbler are made to fit each other in such a man- 
ner that, when connected and under strain, they are held undeviatingly 
as shown in Figs. I and II ; that is, the wire is in the prolongation of the 
axis of the rod. If this be not observed the relation of the leverages of 
the pawl and tumbler will be destroyed, and the detacher may be too 
sensitive, besides which the rod may incline to a degree that will act 
somewhat against a vertical descent. 

II. That part of the lip of the tumbler on which the bail of the shot 
rests should have the edges beveled or rounded, otherwise the edges may 
be broken up and spread, thus preventing the tumbler from being thrown 
back between the side pieces. Thin washers put on either side of the 
tumbler and pawl would probably be tin improvement. 

III. All parts should work freely. 

IV. The bottom of the specimen-cup should have the proper bevel; 
if too sharp it may retain but a small specimen, and if too blunt the rod 
may not penetrate firm material. 

V. The spiral spring H should not be so strong as to prevent soft 
bottom material entering the cup; its strength should he sufficient, ivhen tlie 
rod is lying Jlat, to force the valve smartly to its seat when the valve is imshed 
inward and released, and yet not strong enough to seat it by about one- inch 
when tJie rod is held bottom upwards . The springs for the "Blake's " rods are 
of No. 17 American or No. 18 Stubbs's gauge sp-ing-brass wire; they are 



46 DEP]P-SEA SOUNDING AND DEEDGING. 

three inches in length when not under compression, and have twelve coils 
each. Any spring thus made could easily be adapted to the requirements. 
VI. If desired, the rod might be made considerably lighter for very 
deep work, the present size of the detacher being retained. On the scale 
of Plate 39 the rod and detacher are strong and handy, weighing five and 
one-quarter pounds. The size of the specimen sought should have much 
influence in determining the size of the rod. If only an indication of the 
bottom material were wanted, no specimen for careful examination being 
needed, a rod weighing only two or three pounds would suffice. 

REQUIREMENTS FOR A PERFECT SOUNDING-ROD. 

The following might be added to the list of requirements for a perfect 
sounding-rod : 

I. Certainty of not detaching the sinker during the descent. 

II. Certainty of detaching on striking any character of bottom. 

III. Certainty of not rebooking or of fouling with the sinker, in any 
way, after the same has once been tripped. 

IV. Adaptability to getting a specimen from the various kinds of 
bottom material. 

V. Certainty of not grappling irretrievably with the bottom. 

VI. Certainty of retaining the specimen against the Avash of water in 
the ascent. 

VII. Handiness for extracting the specimen and for cleaning the parts. 

VIII. Freedom from changing its form under the severe pressure in 
deep water. 

IX. &c. Strength, simplicity, cheapness, light weight, and freedom 
from corrosion. 

GENERAL REMARKS ON SOUNDING-RODS AND DETACHERS. 

In general there are two ways of effecting the detachment of a sinker 
from its rod : 

I. By the actual or partial slacking of the sounding wire or rope. 

II. Directly by the impact of the rod against the bottom. 



SOmTDIKCx-WIRE, CORRECTION-CURVE, ETC. 47 

Of these two methods the former is regarded as the safer, l)ut some- 
times botli are involved in one detaching apparatus. 

A detacher which depends for tripping solely on the resistance of 
the bottom material is usually more sensitive on hard than on soft bot- 
tom; also, should the sinker glance on the side of a rock or ledge, the 
trigger or other appliance might not be presented fairly to the blow 
necessary to upset the connection which holds the sinker in place. 

The action of the original detacher by Brooke was based on the 
diminution of the tension on the line. This is the principle applied in 
the Sigsbee detacher, and, indeed, in almost all others approved by per- 
sons of experience in deep-sea sounding. 

That detacher must be very objectionable which will drop the sinker 
before bottom has been reached. In tests made with the Sigsbee detacher 
and a fifty-seven-pound shot-sinker it was found that the latter did not 
fall until the wire had been released from all but eight pounds of the 
weight of the sinker, yet this result always follows when the wire is 
slacked or " rendered " less than one inch. This shows the right kind of 
sensitiveness and gives assurance that the rod will find an entrance into 
most sea-bottoms. 

In sounding with wire it is so important that there should be no fail- 
ure of the sinker to detach on deep-water bottoms, that I am constrained 
to dwell still longer on this subject. In order to show how accidents in 
this regard may be brought about, Plate 4 has been prepared. By taking 
various other rods in consideration the cases might be much extended. 
It must be understood that I have in mind the use of the iron bails or 
slings adopted by the Navy and by the Coast and Geodetic Survey. 

Fig. 1 shows an assumed case wherein the sinker and rod are imbed- 
ded in mud. The bail has been tripped by the single-hook detacher, but 
the resistance of the mud holds it in an upright position. The sinker, 
supported by the mud, does not drop clear, and on hauling taut the sound- 
ing-wire the detacher rehooks the bail. The case applies to a number of 
forms of detachers, but this accident would be much less liable to happen 
were the sinker suspended from the hook by a rope-sling composed of two 
independent legs, each going over the hook with a ring. 



48 DEEP-SEA SOUNDING AND DEEDGING. 

In Fig. 2 the sinker and rod are supposed to be wholly covered with 
mud and at rest in the position shown. Although the sounding- wire is 
slack the pawl of the detacher does not fall because of the resistance of 
the mud; and tliere is no pull from the sinker to force it down. This 
applies to a number of rods. In the Sigsbee detacher the spring N, Plate 
39, is intended to meet this contingency as one of its functions. 

Fig. 3 shows what has often occurred with us, experimentally and in 
actual work, when there was a flat top to the cylinder of the sounding- 
rod. The bail has tripped, but has fouled on the cylinder-head. 

Fig. 4 shows what may happen when there is no provision for pre- 
venting the cylinder from getting furtherwithin the sinker than is desirable. 
That this is possible has been proved experimentally. It could not come 
about with projecting heads or caps like those shown in Figs. 3 and 5. 

Fig. 5. — This accident is possible when the rod is constructed to 
admit the specimen from the side. The sinker has tripped, but has fouled 
on pieces of coral, rock, or gravel protruding from the specimen chamber. 
This has been proved by experiment. 

Fig. 6. — The sinker has tripped, but has fouled on a specimen-cup. 
The accident shown in Fig. 5 may also happen with this arrangement. 
Both cases have been proved. 

Some of the contingencies illustrated are very remote, it is true; but 
by providing against as many as occur to the mind, we not only narrow 
down the list of possible failures, but when accidents then happen we are 
better able to find the real cause by having previously limited the field 
of investigation. 

HEAVY SINKERS FOR DETACHING. 

The sinkers now used on board the "Blake," in connection with sound- 
ing-rods, are cast-iron eight-inch shot, with a hole of sufficient size to give 
a clearance of one-sixteenth of an inch all around the rod, and weighing 
about sixty pounds each (Plate 39). They are cast at the Washington Navy- 
Yard of old scrap material not suitable for ordinary purposes, and cost 
$1.75 each. On those sent us were small lugs or loops — for securing the 
iron-wire bail, or sling — in place of the side holes shown in the plate. The 




SHOWING SOME OF THE CAL'SES-FROBABLE AND REAL- OF THE OCC 
OF SINKERS TO DETACH. 



^SIGNAL EAH.UREy 



SOUNDIiS^G-WIRE, CORRECTIONS-CURVE, ETC. 49 

lugs being cast Avith the shot, the brittleness of the metal was such that 
after a feAv months of stoAvage many of the lugs were found to be broken. 
In order to avoid trouble of that kind, I proposed holes in which to make 
fast the ends of the bails. To replace the wire bails that came adrift 
through the breaking of the lugs, we at first used single rope slings as a 
make-shift, but this causing accidents like that illustrated in Fig. 6, Plate 
4 — for at the time we were using a specimen-cup of the pattern shown in 
the figure — we improvised wire bails, which did well. An advantage with 
a stiff-wire bail is that it will keep its shape from the surface to the bottom 
and after tripping, while with a rope sling in one piece we may expect 
shrinkage when it becomes wet, and possibly dangerous twisting when it 
is released from tension on striking bottom. In Plate 39 we will suppose 
the rope sling to exactly fit over the tumbler when the shot and cone top 
of the cylinder are up as far as they will go. This is the state of things 
when the rope is dry, but when the sinker is lowered into the water the 
sling shrinks and bears down on the tumbler in a way not provided for. 
From this it will be seen that rope slings when employed with a cylinder 
having a projecting top should be of a length to allow for shrinkage, and 
should be made wet before they are hooked to the detacher. All seamen 
know, at least in a general way. the power developed by the shrinkage of 
rope after being made wet. In securing the ends of bails to side holes in 
the shot, as shown on Plate 39. care should be taken that the fit be loose 
enough to allow the bail to fall clear ])y its own weight on tripping. 
Although this is not necessary with the Sigsbee-Belknap detacher and 
cylinder, it is a very proper precaution. A double rope sling is much less 
liable to foul than a single one of the same material. There has been some 
objection made to the use of iron-wire bails, because they do not always 
fall clear in soft mud or clay (Fig. 1, Plate 4). The trouble is not with the 
iron bail, but lies in using it with a rod not adapted to. it. Wo used these 
bails for four years and approved them highly — in fact, we regarded their 
adoption as a decided advance. 

While on the subject of detaching, it is well to mention that the edges 
of the metal, around the cylindrical hole in the shot, sometimes become 
bent inward by rough usage in stowage or transportation; hence an 
7 D s 



50 DEEP-SEA SOUNDING AND DEEDGING. 

additional need of a large clearance. Every shot taken from the lockei 
for use should be examined and fitted to the rod immediately after being 
brought to the upper-deck. A slight beveling of the metal at the exposed 
edges, in the manufacture, would prevent mishaps in this respect. 

Should heavier sinkers than those used by us become desirable, the 
rod (Plate 39) has ample length to admit of carrying a much larger shot. 
Probably the deepest cast with wire might be taken with a sixty -pound shot, 
excepting in very strong currents or heavy seas, when a heavier weight 
would give results more trustworthy. Certainly seventy-five pounds of 
metal should suffice for any possible case. With a steamer, economy of 
time might effect a great saving of coal and of general outlay which could 
not be offset by an occasional gain of a few pounds of old iron, hence 
considerations of economy might vary the plan of operations for different 
vessels. As a rule, a sixty-pound sinker may be pronounced a heavy one 
for wire sounding, and one that will give rapid work up to 3,000 fathoms 
or 3,500 fathoms. In fitting out with heavier sinkers it should be remem- 
bered that the proportion of depths to be sounded exceeding 4,000 fathoms 
is small in comparison with the lesser ocean-depths requiring examination. 

THE GAS-PIPE SOUNDING-ROD. 

There were occasions, in deep water, when we did not wish to save 
a specimen of the bottom soil. At such times we often used a simple rod 
made from a length of i-inch or f-inch gas-pipe, to which was screwed a 
Sigsbee detacher. This would bring up a few particles of bottom material, 
just enough to show the color. It presented very little surface to resist- 
ance in hauling back, and was of such light weight that we gained time 
by its use. If the wire parted, we lost nothing of value but the submerged 
wire and the detacher. With a rod of this kind, to make sure of tripping 
at once on striking bottom, the loAver end of the gas-pipe should project 
through the shot at least a foot; an arrangement which will also provide 
against the bail or sling getting above the detacher. The lower end of the 
pipe may be plugged and armed with tallow, or a ball of rubber or metal 
being slipped inside the pipe the edges of the metal at that end may be 
rounded inwards so as to retain the ball as a valve. In the latter case a 



DEEP-SEA SOUNDING ^\ND DREDGING 
U.S. COAST SURA^V PExVTE 5 



FIG. 2. 



FIG. 1. 





FTG.l. CAiVS FOR OBSERXING CURRENTS. FIG-. 2. SOUNDING LEAD 
FITTED WITH THE STEEUVVAGElSr SPECIMEN CUR 



SOUNDING-WIRE, CORREOTiON-ClJEVE, ETC. ol 

Couple of small holes for water-escape should be bored through the pipe 
just below the detacher. With a similar instrument, when falling short of 
shot-sinkers, we have sounded successfully with old grate-bars, an old ash- 
bucket filled with fire-bricks, &c,, leaving these weights on bottom. Almost 
any piece of old scrap-iron, of elongated form, may be made to serve as a 
sinker by fitting a rope grommet transversely around it at each end, like the 
single strap of a block, and leaving a free eye or becket in each grommet 
through which to pass the rod. For the sling or bail, wire would be best. 

LIGHT-WEIGHT SOUNDING-LEAD FOR RECOVERY. 

When, in sounding with wire, circumstances were favorable to the 
recovery of a sinker, we used a sounding-lead of the common commercial 
pattern, to which we fitted a Stellwagen specimen-cup (Fig. 2, Plate 5). 
The combined weight of the lead and cup was about thirty-four pounds. 
With this kind of sinker we took the greater number of our soundings 
with wire, especially after getting on board a sounding-machine giving us 
the advantage of an accumulator (Plate 7). The hauling back was always 
done by steam. The lead and Stellwagen cup are not the best that could 
be devised for the purpose, as the specimen is sometimes washed out in 
the ascent and the lead is not of the best shape possible. Fig. 2, Plate 5, 
gives a clear representation of the apparatus, which may be described as 
follows: A wrought-iron spindle, sunk for a part of its length into the 
sounding-lead, has a detachable conoidal cup screwed to its lower end. 
Sliding freely on the spindle, between the lead and the cup, is a leather 
washer, which is raised by the resistance of the water in the descent or 
by the resistance of the soil on striking bottom. On the ascent, the washer 
falls by its own weight, or by the resistance of the water is forced down 
upon the cup, thus inclosing the specimen. We generally used a second 
washer, of lead or iron, above the leather, and sometimes adopted a sug- 
gestion by Lieut. R. D. Hitchcock, U. S. N., which was to gather and seize 
a piece of muslin around the spindle above the washers, allowing its folds 
to drape down around the washers and cup nearly to the bottom of the 
latter. This was intended to prevent a current of water between the 
spindle and the washer. 



52 DEEP-SEA SOUNDING AND DEEDGING. 

While much ingenuity has been displayed in designing combined leads 
and specimen-cups that may be operated when it is intended to recover 
the sinker, there is nothing known to me that I think altogether acceptable 
for use with wire, and on all bottoms. It should be remembered, when con- 
sidering the requirements for such a device, that it would be the one most 
often used in depths varying from 100 fathoms to 1,000 fathoms, between 
which depths all characters of bottoms are met with — such as sand, shells, 
gravel," coral, rock, clay, and mud or ooze; also that by retaining the 
sinker the whole force of impact due to the weight and velocity of the 
sinker at the instant of striking bottom is brought to bear on the specimen- 
cup, and unless this crushing-force be provided against the cup may become 
injured by a blow on rock or other hard material. 

More will be said hereafter about hauling back the sinker. 



CHAPTER III 

THE SOUNDING-MACHINE AND ITS USE. 

DESCRIPTION OF THE ORIGINAL SERVICE MACHINE FOR SOUNDING WITH 
PIANO-FORTE WIRE. 

To illustrate in what respect changes were made by me in the sound- 
ing apparatus, an explanation will be given of the machine we first used, 
which was practically the same as those originally issued for general use 
with the sanction of Sir William Thomson (Plate 6). 

A reel having a drum one fathom in circumference (less the small 
allowance for the diameter of the wire) and with a V-shaped friction-score 
at the side is rigidly attached to its axle and mounted upon standards. 
On the axle is a worm which engages a counter or register, to mark the 
revolutions of the reel. The wire, which is wound about the drum, pays 
out directly from the reel — through a fairleader or clamp on the forward 
end of the bed-board — into the water. In rear of the reel, and on the 
same side as the friction-score, is a dynamometer-pulley or wheel having 
two scores, which we will call the wide score and the narrow score, respect- 
ively. This is mounted in a special standard, from which it may be removed 
at will. For paying out wire, an endless rope-belt, called the brake-cord 
or the friction-rope, is passed somewhat more than half around the friction- 
score of the reel, thence one whole turn around the wide score of the 
dynamometer-pulley, and through a tail-block to the rear. The pendant 
of the tail-block — or, more strictly, pulley — being rove through a standing 
block, supports weights to tighten the friction-rope.* The narrow score of 

* Captain Belknap introduced the use of weights for putting strain upon the friction-lhie, a tackle having 
previously been employed for that purpose. 



54: DEEP-SEA SOUKDIKG AKD DEEDGING. 

the dynamometer-pulley is connected with a spring-scales by a tangent wire 
or cord in such a way that the traveling of the belt can turn the pulley on 
its axle only to the extent permitted by the resistance of the spring-scales. 
When the reel is set in motion, the retardation of the belt on the dyna- 
mometer-pulley places a resistance upon the reel that can be regulated 
by weights at the tail-block. The scales are intended to show, approxi- 
mately, the amount of resistance applied to the reel by means of the belt. 
The words of the inventor are quoted to explain the action of the 
machine : 

" The wire is coiled on a large wheel (of very thin sheet-iron galvanized) which is made as light as 
possible, so that when the weight reaches the bottom the inertia of the wheel may not shoot the wire ont 
so far as to let it coil on the bottom. The avoidance of such coiling of the wire on the bottom is the 
chief condition requisite to provide against the possibility of kinks; and for this reason a short piece of 
hemp line, about five fathoms in length, is interposed between the wire and the sounding-weight ; so that, 
although a little of the hemp line may coil on the bottom, the wire may be quite prevented from reach- 
ing the bottom. A galvanized-iron ring, of about half a pound weight, is attached to the lower end of 
the wire, so as to form the coupling or junction between the wire and the hemp line, and to keep the wire 
tight when the lead is on the bottom and the hemp line is slackened. The art of deep-sea sounding is to put 
such a resistance on the wheel as shall secure that the moment the weight reaches the bottom the wheel will 
stop. By 'the moment' I mean within one second of time. Lightness of the wheel is necessary for this. 

"A measured resistance is applied systematically to the wheel, always more than enough to balance 
the weight of wire out. The only failure in deep-sea soundings with piano-forte wire, hitherto made, has been 
owing to neglect of this essential condition. The rule adopted in practice is to apply resistance, always exceed- 
ing by 10 pounds the weight of the wire out. Then the sinker being 34 pounds, we have 24 pounds weight 
left for a moving force. That, I have found, is amply sufficient to give a very rapid descent — a descent so 
rapid that in the course of half an hour or fifty minutes the bottom will be reached at a depth of 2,000 or 3,000 
fathoms. The person in charge watches a counter, and for every 250 fathoms (that is, every 250 turns of the 
wheel) he adds such weight to the brake-cord as shall add 3 pounds to the force with which the sounding- 
wheel resists the egress of the wire. That makes 12 pomids added to the brake I'esistance for every 1,000 
fathoms of wire run out. The weight of every 1,000 fathoms of the wire in the air is 14^ pounds. In water, 
therefore, the weight is about 12 pounds; so that, if the weight is added at the rate I have indicated, the rule 
stated will be fulfilled. So it is arranged that when the 34-pound Aveight reaches the bottom, instead of there 
being a pull, or a moving force, of 24 pounds on the wire tending to draw it through the water, there Avill 
suddenly come to be a resistance of 10 pounds against its motion. A slight running on of the wheel — one turn 
at the most — and the motion is stopped."* 

* Sir William Thomson was the first to discard the m.ethod, already described, of weighing the 
resistance upon the reel. In Captain Belknap's Pacific work a record was kept of the dynamometer read- 
ings, and a number of cases are foiuid wherein the sinker struck bottom, when, accm'ding to the dyna- 
mometer, the resistance upon the reel was less than the weight of the submerged wire. The dyna- 
mometer readings in such cases must have been erroneous, otherwise the reel would not have stopped; 
but since the reel, in fiict, did give immediate evidence of the arrival of the sinker on bottom, it must 
have been that there was resistance upon the reel not shown by the dynamometer. The resistance upon 
the reel not indicated by this dynamometer arrangement is probably due to the following causes : Fric- 
tion of axles or pivots; friction of the working parts of the scales on account of the horizontal posi- 
tion of the latter ; stiffiiess of the brake-cord at the several changes of direction ; and the occasional 
chafing against each other of the two parts of the cord moving in different directions on top of the 
wheel. On board the " Tuscarora " the error was somewhat increased perhaps by taking 



THE SOUNDING-MACHINE AND ITS USE. 55 

Notwithstanding its immediate success under the supervision of the 
inventor, and its complete triumph over rope under the management of 
Captain Belknap, in his great Pacific work, when used for the first time in 
actual service, it is not surprising that even this simple and admirable 
machine should have been thought open to modification or improvement, 
to suit the varying conditions of prolonged work at sea. Sir William 
Thomson cordially invited improvement, and he, himself, gave it quite a 
different form, with additional parts to prevent the crushing of the reel 
and to admit of the vessel steaming ahead while hauling in the wire. In 
describing his experience when reeling in at his first sounding with the 
original machine, he says: 

"After about 1,000 fathoms of wire had been got in, the wheel began to show signs of distress. I tlien 
perceived for the first time (and I felt much ashamed that I had not perceived it sooner) that every turn of 
wire under a pull of 50 pounds must press the wheel on the two sides of any diameter with opposing forces 
of 100 pounds, and that, therefore, 2,240 turns, with an average pull on the wire of 50 pounds, must press 
the wheel together with a force of 100 tons, or else something must give way. In fact, the wheel did give 
way, and its yielding went on to such an extent that when 500 fathoms of wire were still out, the endless 
cord which had been used for hauling would no longer work on its groove." 

ATTEMPTS TENDING TOWARDS THE IMPROVEMENT OF THE SOUNDING-REEL. 

The galvanized sheet-iron reel was soon abandoned by Americans 
because of its weakness, and because Captain Belknap had given the 
opinion that a heavier reel might be employed. The Navy at first made 
a brass reel, weighing, when equipped with worm and ratchet-wheel, 
about eighty-seven pounds. That proved to be too weak for depths as 
great as 2,000 fathoms, and it was also supposed that a galvanic action was 
set up between the brass reel and the steel wire. The Navy then made a reel 
in which a cast-steel drum and friction-score in one piece were shrunk upon 
a cast-iron wheel of twelve spokes. This reel is still in use, but, in my opin- 
ion, is much heavier than it need be. It weighs about one hundred and 
fifty-five pounds when equipped, whereas the original galvanized sheet-iron 
reel weighed, when similarly fitted with worm and ratchet-wheel, but twen- 
ty-seven pounds. When the "Blake" was provided with the Navy steel 

the tail-block a long distance to the rear. The scales used may have been graduated when the axis of the 
spring was vertical ; if so, the scales would have registered a trifle too low with the axis horizontal. I thus 
notice the imperfections of this dynamometer, because there still exists a mistaken opinion that it is very accu- 
rate, notwithstanding its abandonment by Sir William Thomson. 



56 DEEP-SEA SOUNDING AND DEEDGING. 

reel, we at once removed every alternate spoke and turned down other 
parts, reducing the whole weight about thirty pounds. For paying out 
in a heavy sea the advantage of speed, combined with safety, was ob- 
viously with the lighter but weaker brass reel. From our experience I 
was convinced that a reel could be devised which would combine lightness 
for paying out with enough strength to resist the accumulated crushing 
force of reeling in, thus permitting the abandonment of accessories for re- 
lieving the reel from a part of the strain when reeling in from great depths. 
In a late form of the apparatus, by Sir William Thomson himself, this 
dangerous accumulated strain is avoided by taking a number of turns of 
the wire around an auxiliary or strain pulley, from which it is passed to 
the reel with the tension very much reduced. 

The new steel reel, Plates 16 and 17, was designed with a view of test- 
ing the practicability of my views, and the very severe test which it has 
withstood seems to indicate that it will suffice for the purpose intended. 
The new reel will be fully described in this chapter. When we consider 
that the -reel and its coil of wire really constitute a fly-wheel, which by 
its weight and rapid revolution gathers considerable momentum, we can 
readily see why a light reel possesses an advantage over a heavy one for 
paying out wire in deep-sea sounding. The momentum of a heavy reel 
becomes an antagonistic feature of much importance at the instant the 
sinker strikes bottom, when the reel should stop quickly ; and likewise at 
times when the sudden downward motion of the vessel towards the side 
where the machine is set up is liable to admit, for a second, of a more rapid 
paying out of the wire than the submerged weights will take off the reel 
under tension. If the wire slack, several turns of it may fly from the 
drum, causing kinks and involving delay, if not loss. Since we cannot 
divest the drum of the weight of wire that it contains — which, however, 
becomes lighter as the process of paying out continues — and since the drum 
itself must have considerable weight that strength may be secured, it seems 
probable that a governor to control the motion of the reel may be em- 
ployed to advantage. In the Sigsbee improved form of the sounding-ma- 
chine for wire, herein shortly to be described, it will be shown that the 
accumulator operates as a governor to check the momentum of the reel at 



THP5 SOtTNDING-MACHmE Ai^B ITS USE. 51 

the right tmie when paying out wire, and that it performs the same function 
at the instant the sinker has reached bottom. 

THE STRAY-LINE AND THE METHOD OF SPLICING IT TO THE WIRE^ 

The piece of rope mentioned by Sir William Thomson, as connecting 
the sinker with the wire to prevent the latter from coiling on bottom, is 
called the '^ stray-line ^ We usually made our stray-line ten or twelve 
fathoms long and from any small stuff slightly less than one-quarter of an 
inch in diameter. The iron ring for joining it to the wire, mentioned by 
Sir WilHam Thomson, proved a failure on board the "Blake." As the 
ring passed through the fairleader, on the forward part of the bed-board 
of the original machine, it was necessary to slow down the reel in order to 
avoid fouling the ring and thus parting the stray-line. At such a time there 
would be only about eighteen inches of wire off the reel to sustain the ten- 
sion and torsion caused by the resistance and gyration of the sinker in the 
water, and the consequence was the loss of the rod and sinker on several 
occasions by the parting of the wire. In sounding from a large vessel this 
might not happen, but the rolling and pitching motions of the "Blake" 
were so quick that we found it necessary to make a change, and we hit upon 
the method of splicing the wire directly into the stray-line, as shown on 
Plate 41. This permitted a rapid unreeling from the first; no slowing down 
nor stoppage being needed as before. The objection to. the ring in our case 
applied equally to reeling in. We used no weight at the end of the wire, 
although to do so certainly seems a proper precaution. I recommend the 
use of a small weight for the purpose stated by Sir William Thomson; and 
suggest that several small pieces of lead, weighing in the aggregate one 
pound, be strung upon the stray-line as upon the roping of a seine, and that 
they be fastened at a distance of four or five fathoms from the end of the 
wire. Disposed in this way there will still be one or two fathoms of the 
stray -line upon the drum when the leads are passing through the fairleader, 
and then, should the reel be slowed down for the moment, any torsion, 
as found in our experience, will come upon the rope. Once the leads are 
through the fairleader the wire may be allowed to pass off quickly, and 
8 D s 



ij8 DEEP-SEA SOUNDING AND DREDGING. 

torsion Avill be of no aceouiit after several fatlioms of wire liave Ijeeii un- 
wound.* 

To splice the wire into the stray-line (Plate 41) make a single-wall 
knot in the latter, and whip the rope with twine for a half inch below the 
knot; tuck the end of the wire down through the middle of the single-Avall, 
and complete the knot by jamming the strands, working close down to the 
whipping. Beginning close up under the knot take ten or twelve turns of 
the wire around the rope against the lay, then tuck it through under a 
strand and make another set of turns below the first set, this time wdth the 
lay of the rope: then tuck and repeat against the lay, and expend the end 
of the wire. Taper and whip the ends of the strands about the wire above 
the knot and the splice will be complete. These we used for nearly four 
years, and they are still used on board the ''Blake." They have to bear only 
the weight and resistance of the rod. sinker, stray-line, and instruments 
fastened to the latter, and since one of them well made withstands the test 
of a heavy man's weight, they are strong enough. I think it well that they 
should not be so strong as the wire itself, for should the rod or lead foul 
irretrievably on bottom, if all parts of the stray-line and wire were equally 
strong the latter would part just at the machine, where the greatest strain 
comes, while with one of these splices there would be a chance of parting 
at the stray-line. In fact, our wire was several times saved in this manner. 

REMARKS ON THE SIGSBEE MACHINE FOR SOUNDING WITH WIRE. 

The remarks and description which follow, concerning the Sigsbee 
sounding-machine, are taken mainly from a letter written by me to the 
Superintendent of the Coast and Geodetic Survey in 1876, which was after- 
wards published as a Bulletin of the Museum of Comparative Zoology of 
Cambridge. Mass. (vol. v. No. 8), at the instance of Prof. Alexander Agassiz. 

In June and July, 1874, I read the reports made by Captain Belknap 
to the Bureau of Navigation, Navy Department, detailing the working of 
the original Thomson sounding apparatus in the operations in the Pacific 
with the "Tuscarora," in 1873-74. While it was evident that this machine 
for sounding by means of wire gave remarkable results as compared with 



* With tlie Sigsbee soancliiig-tnachine no slowing down for the purpose stated is necessary, although the 
•1 should not be allowed mucli speed until the weights are clear. 



t^ O z; 
D - 5 




> 



THE SOUNDING-MACHmE AND ITS USE. 59 

rope-sounding, its mechanical success was apparently due in a great degree 
to the intelligence, patience, and skill of Captain Belknap and the officers 
who assisted him. A study of Captain Belknap's reports suggested to me 
the idea of improving the machine in order that it might be worked with 
fewer demands on the watchfulness and ingenuity of those having it in 
charge. Captain Belknap having been forced to reel in by hand, it occurred 
to me that if the wire were connected with an accumulator, interposed 
between the reel and the sinker, to show the strain upon the wire at all 
times when reeling in. and to ease the sudden jerks caused by the oscillating 
motion of the ship, steam might be applied for reeling in, and .thus the 
labor and difficulty attending this operation by hand might be obviated. 
My views were communicated to the Superintendent, who at once approved 
them. Under instructions from him, a machine having an accumulator 
was designed during the summer of 1874, and. as the drawings advanced, 
other ideas were incorporated with the original plan. From my drawings, 
a machine for experimental purposes was made in the winter of 1874-75 
(Plate 7). This was used for three years on board the " Blake," and, as we 
had previously used the original Thomson machine (Plate 6) for six months, 
opportunity was afforded for comparing the relative merits of the two. Some 
faults arising from bad mechanical arrangement had first to be corrected 
in the Sigsbee experimental machine, after which, even under the most 
unfavorable circumstances of wind, sea, and current, it performed as had 
been anticipated. This machine being experimental and open to such 
improvements as experience might suggest, it was always intended, if suc- 
cessful, to replace it by one embracing these improvements. Accordingly, 
drawings were prepared during the summer of 1876 to this end (Plates 36, 
37, 38), but, for various reasons not necessary to be recited, the machine 
was not made until just before my detachment from the survey, so that I 
have never seen it at work (-Plates 8 to 15, inclusive). 

Since this book was commenced Commander Bartlett, my successor on 
board the "Blake," has used tlie new machine for six hundred and sixty- 
four casts, in depths from one hundred to 3,000 fathoms, many times under 
trying circumstances in trade-wind seas about the Windward Islands of the 
Caribbean Sea. Commander Bartlett and others onboard the "Blake" 



60 DEEP-SEA SOUNDING AND DEEDGING. 

agree in representing its working as wholly satisfactory. Among the 
"Blake's" officers who have rendered these favorable opinions are those 
who have operated the Sigsbee experimental machine also, and one who 
has worked both the original Thomson machine and the Sigsbee experi- 
mental machine. It is highly probable that so small a vessel as the ''Blake " 
must have been very lively in the seas she encountered during her recent 
cruise ; hence if a governor on the motions of the sounding-reel possesses 
any advantage, it must then have been needful on board the ''Blake," 
particularly as most of the work was done with a reduced Navy steel reel 
weighing, independently of the wire, at least one hundred and twenty-five 
pounds. Of the governing action of the new or latest form of the Sigsbee 
machine the opinions cited were most favorable. 

I will state briefly that the experimental machine was the same in prin- 
ciple as the new one, shortly to be described, but in the latter spiral springs 
have been substituted for the helical springs used in the former; there has 
also been added to the new machine a strain-pulley to prevent the crushing 
of the reel, and a swivel-pulley to admit of the vessel steaming ahead on 
her course when reeling in the wire. The idea of using these two pulleys 
was obtained from Sir William Thomson's machine in its form as improved 
by him after Captain Belknap's cruise, but Sir William Thomson's mode 
of construction was departed from in order to suit the different shape of my 
apparatus. The modification or improvement made by me on the original 
Thomson sounding-machine lies chiefly in the employment of a peculiar 
kind of accumulator, and its adaptation to the various uses of accumulator, 
dynamometer, brake, correct register, and governor. The accumulator 
eases the jerks that may be brought upon the wire while reeling in, and as 
a dynamometer it shows the strain upon the wire at each, instant during the 
same operation. The brake gives a handy means of applying resistance to 
the reel without weights, and, with its attachment of spring scales, provides 
a second dynamometer, which, during the operation of paying out, shows 
the tension upon the wire and the resistance which the reel suffers. The 
brake, in connection with the accumulator, operates as a governor on the 
motions of the reel when paying out wire. The odometer, used as a register 
in a special place, gives, without interpolation, the amount of wire played out. 




> 

H 
W 
CD 



THE sou:nding-machine and its use. 61 

It may be stated, after four years' experience in deep-sea sounding 
with wire in a small steamer, that these changes and additions, excepting, 
perhaps, the use of the odometer as cited, are desirable and of sufficient 
value in prolonged work to warrant their extra cost. With the experimental 
machine (Plate 7), eight hundred and twenty-four soundings were taken 
in weather varying from calms to gales, and with scarcely any annoyance 
whatever. The latest form of the Sigsbee machine (Plate 8) , being more 
compact and having less friction in its Avorking parts, has been found to 
be more convenient. 

In comparing the original Thomson sounding-machine for wire (Plate 
6) with the Sigsbee form of the machine (Plate 8) the following points have 
been established. 

I. For reeling in the latter has the advantage at all times. 

II. For paying out when there is no distinctly perceptible rolling or 
pitching motion on the vessel, there is no gain worth mentioning-, except- 
ing at the instant of striking bottom. 

III. When there is such motion the advantage is largely in favor of 
the new machine — greater in degree as the motion becomes excessive. 

IV. In handiness the comparison is always in favor of the latter. 
Before passing to a detailed description of the new machine it is proper 

to state that my efforts to improve the sounding-machine have been made 
in the interest of good work, and that the kind manner in which Sir Will- 
iam Thomson has been willing to receive co-operation in improving the 
apparatus has been very encouraging and gratifying, although nothing less 
could have been expected from that distinguished scientist. I have already 
stated that, in point of accuracy, the original form of the machine by Sir 
William Thomson was successful from the first, and it is particularly to 
be understood that the sufficiency of the original machine in that respect 
is fully recognized. 



62 DEEr-SEA SOUNDING AND DEEDGING. 

DESCRIPTION OF THE LATEST FORM OF THE SIGSBEE SOUNDING-MACHINE. 

(Plates 36, 37, 38.) 

The Reel (A, Figs. I, II, III, IV, aiid V) is, for convenience, one fathom 
in circumference of drum, less an allowance for the thickness of the wire; 
that is, the initial turn of wire taken around the bare drum measures 
exactly one fathom in length. At the side is a score, which is V-shaped in 
cross-section, for receiving the friction-line. The reel is rigidly attached to 
its axle by a key, and for each end of the axle a crank should be provided. 
The drawing was made from the Navy brass reel, the form of which is not 
now approved. (For another style of reel see Plates 16 and 17.) 

If the key by which the reel is iittaclied to its axle be made to admit of easy removal, the axle may be 
withdrawn when the reel is to be stowed in the tank of oil or lime-water. In this way a smaller tank may be 
used. For a description of the tank ordinarily used see Chapter II. In the machine made for the "Blake" the 
axle rests on friction-rollers. This is not necessary, but it ^ives a very smooth movement, and, by lessening the 
ft'iction of the axle, a more accurate indication of the amount of resistance upon the reel, when paying out, is 
given by the readings of the two scales to be described hereafter. 

I7.e Register for the Axle of the Reel (B, Fig. 1). ThlS is thC SaUlC iu COU- 

struction as the register used by Sir William Thomson on the original 
machine, but it is marked differently. (See drawing, Plate 38, on which, 
however, the thousands dial has been marked in tens where it should have 
been marked in unit's.) A worm on the axle of the reel engages the gearing 
of the register. Since the record of the instrument gives only the revolu- 
tions of the reel — turns, not fathoms — a correction-curve (Plate 41) or 
other means of reduction must be employed in order to ascertain the true 
length of wire payed out at a sounding. For ;i ready method of measure- 
ment see Odometer in the course of this description. 

The Reelinuin or strain J^ullev (C, D, E, FlgS. I, IV, V). CompOSCd of 

three separate pulleys, C, D, and E; the score E, for the wire; the score C, 
for a rope belt to connect with the friction scoreof the reel, if desired ; and the 
score D, for a rope belt to connect with a hoisting-engine. The two ])elts 
are shown " brought to"" on Plate 13. For eacli end of the axle a crank 
should be provided. The axle is made in two parts, squared and slotted 
to clutch each other. That part which sustains the pulleys is free only to 
revolve in its bearings, while the other, besides revolving, slides in its bear- 



THE SOUNDING-MACHINE AND ITS ITSE. 63 

ing ill the line of its axis to admit of unclutching, tliat tlie wire and 
belts may be ''brought to" on the strain-pnlley. (Fig. V.) 

The scores V niid 1) sliould be V-sliaped in ei'oss-s 
' of a cai.stau or of a wineli-liea.l. I do not full v believe ii 



aiisxv.MiM.u tlie eoiiditious of weigbt and strengtb. As hu 
Inindi-eil pounds nmy be fixed upon as tbe weiobt beyond 
Tills inelndes tbe axle and Kttings and assumes a well-piv 
eoil of wiiv. Within this limit great strength may be see 
the latter is m.t yet e^^/reZ// rertain. an.l t,. increase the 
doubtful expediency, it is, perhai)s, not saf,. to advise th 
The strain-pulley i.'laeed U]>on the •• Blake's ■' new soundi 



The score E sho 
essity for a strain 


uld be 1 
pulley 


■ounded li 


ke the 


barrel 
s only 


ushing force whi, 


if we 1 


',"i'a rr 


a be br 

■ IJlakc 

rts of ; 

ts; but 


ought 
■torily 


t is not advisabl,. 
i-olmbly enough f, 


HE; 


hide the V 


I reel, 
of the 

s is of 


,se of the strain-i 
bine was added i 

fsbeennichine tha 


inlley 1 
nore fo 


.e wholly 

■el shown 


ixiuiid 

on I'la 


ished. 
an for 
of the 
tes 16 






of the , 



stitution for the present strain-pulley of a steam-engine, similar to tlnat shown on Plate 18, of which a description 
will be given in this chapter. If the tly-wheel of this engine were given the three grooves menticnied, either of 
the above modifications would possess all the advantage of an independent strain-pnlley, ami either might be 
employed with equal facility for the same purpose. 

Tlie Aecumuiatoi: — CoHiposed of the tubes F, F, F, &c. (Figs. I, II, III, 
IV, V), containing the spiral extension-springs G, G (Fig. Ill) which con- 
nect with the movable cross-head H (Figs. II, VII, VIII, IX) by means of 
the chain, or wire rope, I, I (Figs. I, II, III) passing over the pulleys J, 
J (Figs. I, II, XII). The tubes are hinged at K, K (Figs. I, II, III, IV) 
that the upper sections may be lowered for convenient stowage ; they 
may be graduated for the number of pounds pull on the wire, either the 
upper or the lower arm of the cross-head being made the index. There 
are three sections to each -tube, the lower section of each, beneath the 
bed-board, unscrewing for stowage or transportation (Plate 12). The 
cross-head H, containing the pulley L (Figs. I, VII, VIII, IX), moves on 
the steel guides M, M (Figs. II, III, V, XI), which are fastened by screws 
to the tubes. The pulley L is rigidly attached to its axle by a key. To 
the axle is attached an odometer, N (Fig, II, Plate 37, and drawing on 
Plate 38). This pulley is exactly one yard (one-half fathom) in circum- 
ference on its drum, less the allowance for thickness of wire. One-half 
the number of revolutions of the pulley, as shown by the odometer, will, 
therefore, give at once the number of fathoms of wire payed out or reeled 



64 DEEP-SEA SOUNDING AND DEEDGING. 

in. The action by which the accumulator operates as a governor will be 
explained when the method of taking a sounding is described. 

The extension-springs used in tlie accunnilator are eacli twenty-eight and a half inclies long and 1\vo and 
an eighth inches outside diameter; they are made of No. 4 (American gauge) steel wire; each weighs eight and 
a quarter pounds, and has a movement of four feet (approximately) for a strain of one hundred and fifty pounds 
directly applied. When the purchase is considered, it is seen that a pull of one hundred and fifty pounds on the 
wire will move the cross-head four feet, which will correspond to a rendering or cushioning of the wire a dis- 
tance of eight feet. Thinking that these springs might he found too stiff, a couple of spare sets were provided 
the "Blake," which were made from smaller wire hut on the same mandril used in the manufacture of the first 
set. A single spring from one of the spare sets gave a movement of four feet for one hundred pounds strahi, and 
from the other spare r°t an equal movement for eighty pounds strain. The original pair seem to have done well, 
however. The springs were made by John Chatillon & Son, 91 Cliif street. New Yoik, at a cost of about $12 

The upper section of each tube is of two and a half inches inside diameter and an eighth of an inch thick- 
ness of metal. The two lower sections are the same as the others in inside diameter but are a quarter of an inch 
thick. 

Within the limit of its elasticity the movement of a spring varies as the strain; hence the tubes of the 
sounding-machine may be graduated for the number of pounds of strain upon the wii-e as follows : Reeve the 
end of the wire from the reel over the cross-head pulley and pawl the reel. Hang a weight of twenty. 
five pounds from the end of wire, the and mark the point on one of the tubes opposite which the upper 
arm of the cross-head comes to rest, which point we will call A. Increase the weight to one hundred 
poiuuls and mark the corresponding point on the tube indicated by the upper arm of the cross-head, 
which second point we will call B. Lay off on a thin strip of wood or metal the distance A B, and divide 
this distance into seventy-five equal parts. Each division will correspond to a strain of one pound on the wire. 
Continue the same scale above the point A and below the point B. Lash the strip of wood to the tube so that 
the point A on the former will coincide with the point A on the latter. The upper arm of the cross-head will be 
the index. 

Sliould the rope by which the cross-head is suspended stretch or shrink thereafter, add twenty-five pounds 
to the wii'e as before, and determine the position to which the point A of the tube has shifted. Having deter- 
mined the new point A on the tube, bring the point A on the strip of wood to a coincidence therewith, and the 
graduation will have been corrected. 

It is obvious that to get a sensitive accumulator dynaniometer, or governor, it is necessary to keep the 
weight of the cross-head and its pulley as light as strength will permit. There will be very little lateral strain 
upon the cross-head other than that due to its own weight when the vessel is heeled. 

The cross-head pulley should be so made as to permit its removal from the cross-head without unshipping 
the latter from the guides. Figs. VII and IX show an arrangement to prevent the wire from flying off the pulley, 
in which the small spiral springs should be very supple. 

O, O (Figs. II, VII, VIII) are shoulders, to guard against the bending of the cross-head in the event of 
parting the chains or ropes I, I, or of parting the wire. Should the chains part the cross-head would fall, the 
lower shoulders striking on the studs P, P (Figs. II, III, V, and also Plates 8 to 11 inclusive). Should the 
wire part while reeling in, the cross-head on flying up would receive the blow against the upper shoulders, 
the latter strikhig against the cross-piece upon which rest the pulleys J, J. On the " Blake's " machine a 
piece of rubber is fastened under the cross-piece to ease the shock. On the latest machine — on board the 
" Blake" — the studs P, P constitute buffers. A hole is bored in the upper end of each stud in the line of the 
axis of the stud, into wliirh a spiral compression-spring is placed. A simple piston cut from a cylindrical steel 
or ii-on rod. (if a size tn lit loose in the hole, is allowed to rest on the spring and project above the stud. Per- 
haps the i)laiii stud ra|i|i<'d with rubber or padded canvas would do as well. 



The Swivel Ptiuey. — The object of this pulley, S (Figs. I, II, V), is to 
alloAv the wire to be reeled in while the vessel is steaming ahead. A sleeve 




> 

W 
CO 



^^•- 



THE SOUNDING-MACHINE AND ITS USE. 65 

of steel, or case-hardened iron pipe, is fastened to a casting that is bolted 
to the bed-board. This sleeve, which is a fairleader for the wire, has, slid- 
ing freely around it, a brass or iron collar to which is bolted the arm 
holding the pulley. In the positions shown in Figs. 1 and V the pulley 
is ready for reeling in, and it may be swung latterly to any desired angle 
(see also Plates 11 and 13). The score will always be in the same line 
with the score of the cross-head pulley. Before paying out the wire — or 
before reeling it in if it be not intended to steam ahead during the opera- 
tion — the arm T, which holds the swivel pulley, is released from the bolt U, 
when the arm will pivot on the bolt V. The pulley should then be lifted 
clear of the wire, turned to one side, and secured (see also Plates 9 and 10). 
The SMiing-scaieg (W aud X, Figs. I aud IV). — In paying out the wire, 
the difference between the readings of the scales W and X gives the num- 
ber of pounds of resistance imposed upon the reel by the friction-rope at 
the instant of taking the readings. 

Tlif scales slinulil lie of tlie kind tliat hav,- a long nioveuu'iit of the index, or iioiuter, for a small exten- 
sion ,.f the rontaiiied spring, and they should he strong .Miough t<i withstand the sudden pulls that may be 
brought upon tliem by the governing action of the a.-ruinulator in heavy seas. lu the maimer of attaehiug the 
frictiondine to them, "as shown in the drawing. th<- s,-ales might slew so as to pre.sent the dials of the twb 
instruments in different i.lanes ; it would, tlieref.re. he well to use braided stuff tor frietion line, at least for 



that part of the frictiondine wdiich rests in tlie .score of the i-eel. Any seaman could attach tlie line to suit the 
circumstances of the case. 

Excepting during our first season, we used no means of measuring the ivsistance placed upon the reel. 
This would seem to have been taking a great risk, but we never had any trouble therefrom, nor were we 
ever in d.mbt as to the actual time of reaching bottom. It is advisable, however, that .scales be used, at least 
until experience has taught at what i-at.- it is safe to alh.w the wire to rini out. aud no assiu'ance is given for 
casts deeper than have been taken by the •• Ulake.- ,S,,undings fr.mi that vessel have been taken in dei)ths 
of 3.00(1 fathoms without using scales, the sinker having struck bottom when the wir,. was rumiiug out at the 
rate of one hundred turns in 1 miiuite IH .seconds. My inforuuuit states that the instant of reaching bottom 
was obvious, as in previous casts. It was my intention to .levise a differential spring-scales to show the 



hod of 1 



surmg 



the resistaiu'c upon the reel by means ,,f two scales, as shown in my drawing, is more exact 
than any other that has been employed, although there is the practical disadvantage ,,f having to (a)tain 
simultaneous readings when the indices are not likely to be alt.igether steady. Jn practi,-e. it will oidy he 
essential to read the instruments occasiomdly. By the habitual use of scales, and by keeping a systennitic 
record of their readings with sinudtaueous readings of the dynamometer: the length and weight of the sid)- 
merged wire; tlie length and weight of the whole amount ..f wire in actual use: si/A- and ns eight of reel, rod, 
sinkers, &e., important data would be secured. In the Sigsbee ex])erimental s.Hinding-machine the friction of 
the several moving i)arts was to<, great to admit of weighing the strain on the wire closely enough to be of 
service in this respect, but in the later machine the dynamometer is sutticiently accurate, the aci-umulator being 
simply a large spring-scales with luit little friction in its working jiarts. 

Ttie Otlotneter; giving the eovrect length of ivire payed out, ivithout veilnetiou 

(N, Plate 37, and drawing, Plate 38). — This instrument is fitted to clutch 

I) D s 



66 DEEr-SEA SOUNDING AND DEEDGING. 

the axle of the cross-head pulley with a spring snap. It records the 
revolutions of the pulley. 

The kind used by us is known as Hunter's odometer. They may be purchased of James Green, 
instrument-maker, No. 20 West Fourth street. New York. In their usual commercial form they must be 
taken apart with a screw-driver for resetting the dials, but, at my request, Mr. Green made them as shown 
on Plate 38 ; that is, to admit of a convenient readjustment to the zero point by means of the milled-head 
screws. Their cost is from $14 to $17. In purchasing a register or odometer it must always be observed if the 
numbers on the dials increase in a direction to correspond with the direction of rotation of the reel or pulley on 
which they are to be used. A description of the odometer may be found in Knight's American Mechanical Dic- 
tionary, vol. ii, page 1544. Instead of the two cog-wheels having, respectively, one hundred and one teeth, as 
there described, they have ninety-nine and one hundred teeth, respectively. 

The machine shown on Plates 8 to 15 was made for the Coast and Geo- 
detic Survey by Mr. Daniel Ballauf, of Washington. It is an elaborate affair, 
made by the most skillful mechanics (model-makers), and is handsomely 
finished throughout. In fact, in point of workmanship, it is such a machine 
as would naturally be employed on board a vessel devoted almost exclu- 
sively to the performance of the work for which the machine is designed. 

Mr. Ballauf submits the following prices for which he will manufac- 
ture a single machine, the standard of workmanship being that of the 
"Blake's" machine: 

Machine complete, as shown on Plates 36, 37, and 38, including steel 
reel shown on Plate 16; register, Plate 38; clamp, Plate 36: the various 
castings and parts to be made of iron, steel, or brass, as may be best, $750. 

If from the above the whole strain-pulley arrangement be omitted the 
cost will be $675. 

If the strain-pulley arrangement be omitted, and a grooved spur fly- 
wheel be substituted, the cost will be $725. The cost alone of the new 
steel reel, Plate 16, Mr. Ballauf fixes at $125.* 

* Mr. Ballauf is now constructing two of the Sigsbee sounding-machines, one for the Navy and the other 
for the Coast and Geodetic Survey. The bed and nearly all other parts are made of steel. A nmnber of mod- 
ifications or improvements are introduced, and the machine folds in a box the dimensions of which are: length, 
4 feet 4 inches; breadth, 1 foot 8 inches; depth, 2 feet 7 inches. In these machines the pipes will be of the 
same height above the bed as in the machine shown on Plate 8, but will not extend below the bed. The strain- 
pulley arrangement is done away with, and in its place is added a small vertical engine similar to that shown on 
Plate 18. The cost of each machine and all its accessories, at the present high price of material, is eleven 
hundi'ed dollars, including: — machine complete, with springs and spring-scales; one spare spring and one spare 
spring-scales; steam-engine fastened to bed; tightening pulley for rope-belt; swivel pulley to fold back, and 
supplied with clamp shown on Plate 36; steel reel shown on Plates 16 and 17, with register shown on Plate 38 ; 
galvanized-iron tank for holding the reel and preserving fluid; box for stowing the machine, and several other 
small accessories or appliances. The steam-engine and the tank account for a part of the increased cost, the 
former costing $225. 

April, 1880. 



THE SOUNDTKCt-MACHINE AND ITS USE. 67 

Mr, Ballauf employs only the most skilled mechanics, men capable of 
making the most delicate instruments, and, therefore, getting high pay; 
hence it may be possible that the prices fixed by him are not so low as 
might be named elsewhere. 

The "Blake's" machine stows, for transportion, in a box the dimen- 
sions of which are five feet nine inches, by two feet nine inches, by two 
feet one and one-half inches. If, however, the cross-head is to be left on 
its guides in transportation, as shown on Plate 12, the box will have to be 
made six feet long. The machine is complete as stowed, no accessories 
being required other than those stowed in the box, excepting the steam- 
engine and tank, which are not included in the prices quoted. 

The original Thomson machine, as made in the United States, stows 
in a box the dimensions of which are four feet four inches, by two feet 
nine inches, by one foot seven inches, accessories not included, and is of 
less weight than the Sigsbee pattern, although more than one hundred 
pounds of lead or other material are needed for applying strain to the 
friction-rope of the former. 

Sir William Thomson's later form of what has been styled the original 
machine — to which he has added the swivel or castor pulley and the strain- 
pulley — takes more room for stowage than either of the above. Rapid 
and safe work he seems justly to regard as of more importance than the 
saving of a small amount of cubic space. The small space required for 
a sounding-machine for wire is hardly to be compared with that formerly 
taken up by sounding-rope and its apparatus. 

TO TAKE A SOUNDING WITH THE SIGSBEE SOUNDING-MACHINE. 

(Plates 36, 37, 38.) 

The reel containing the wire and stray-line being in its bearings, reeve 
the end of the stray-line up over the cross-head pulley, from inboard to 
outboard, and thence down through the fairleader which forms part of the 
attachment of the swivel-pulley. Secure the end of the stray-line to the 
sounding-rod. 

Ship the pawl into the ratchet-wheel that is on the axle of the reel. 
Place the friction-line over the friction-score as shown in Figs. I, II, IV, 



68 DEEP-SEA SOFKDING AND DEEDGmG. 

and from the scales W reeve the hne under the pulley Y on the same 
side of the bed as the friction-score; thence up and over the pulley Q, and 
down under the other pulley Y (Figs. I, II, III, and V). By means of the 
hauling part of the friction-line haul the cross-head well down on the 
guides against the resistance of the accumulator-springs G, G, to insure 
a large surplus of friction on the reel at the time of starting the sounding. 
Make fast the hauling part of the friction-line to the cleat Z (Figs. I, IV, V). 

Connect the sinker with the sounding-rod — having previously cleaned 
the specimen-cup thoroughly — and get them over the side of the ship, 
letting the stray-line take the whole weight. Plates 8. 9, and 10 show the 
machine fully prepared for paying out. 

See that the register and the odometer are properly set. 

If desired, the shot may be lowered slowly to the water before paying 
out regularly, always remembering to set the register and the odometer 
properly. This was our usual custom when the vessel had considerable 
motion, the object being to prevent the shot pounding against the side of 
the vessel. Attend the friction-line, throAvback the pawl, and let the reel 
revolve slowly until assured that everything is working well, when ease up 
the friction-line cautiously: keep the wire vertical, and follow out as nearly 
as practicable the rule governing the amount of resistance to be applied 
to the reel. (See Sir William Thomson's remarks, page 54.) 

If a weight has been attached to the stray -line to prevent the kinking 
of the wire, be careful not to let the reel revolve rapidly until this weight 
is through the fairleader. Avoid any stoppage just as the end of the wire 
is leaving the reel. 

It is impossible to say how fast the wire may be allowed to pay out, 
since the limit of safety varies with circumstances, depending on the weight 
of the reel and its contained wire, the weight of the sinker, the state of the 
sea, the extent and rapidity of the ship's rolling and pitching motions, &c. 

To prevent the wire flying from the drum of the reel when paying 
out — an accident which sometimes happened to us on board the "Blake"' 
when using the original machine — the Sigsbee machine is arranged to oper- 
ate as a governor on the motions of the reel. The action of the governor 
may be explained as follows: If the ship roll downward on the side where 




r 
> 



THE SOUNDINCt-MAOHINE AND ITS riSE- B9 

the machine is set up the strain upon tlie wire is thereupon lessened, and 
the consequent effort of the cross-head to rise — imparted by the reaction of 
the springs — is transferred to the friction-Une. Tiius a greater resistance 
is automatically placed upon the reel, checking its speed or stopping it 
altogether — rarely the latter — until the rising of the vessel or the slowing- 
down of the reel causes an increase of strain upon the wire. As the strain 
increases the cross-head is borne down, which eases the pull on the fric- 
tion-line, allowing the reel to revolve more rapidly; and so on with recip- 
rocal effect. When the vessel is quiet the accumulator has no inherent 
capability of varying the amount, of resistance upon the reel. This alter- 
nating movement of the cross-head when paying out is, of course, scarcely 
perceptible to the eye. Although the effect of the governing action on the 
motion of the reel is distinctly seen, the motion is not fitful, but remark- 
ably smooth. No instance is recalled of the wire jumping from the drum 
of the reel when using the governor. Commander Bartlett, during his six 
hundred and sixty-four casts with wire, met with no such accident. 

From what has been said it follows that the operation of paying out 
is progressing safely if several ])ounds of surplus j^esistance is ujoon the reel, 
according to the rule, and the wire is keeping constantly under tension. 

It appears by the records of work done in the Navy that the recom- 
mendation of Sir William Thomson to use a weight at the end of the wire 
has been held in practice, as much as four pounds sometimes being used. 

If such a weight, or any other considerable weights — as water cups, 
&c, — be used on the stray-line or wire they should be taken into account 
in applying the resistance. The sinkers and sounding-rod being the only 
weights which are to be permitted to reach the bottom, all other sub- 
merged weights should be counterbalanced at the reel. 

With the original sounding-machine for wire, when bottom is reached 
the weight of the sinker and sounding-rod ceases to act as a moving force 
for the reel ; hence, if a resistance slightly in excess of the weight of the 
submerged wire and its attachments — above the rod and sinker — has been 
placed upon the reel the latter will stop. In the same case, with the Sigsbee 
form of the machine, the weight of the sinker and sounding-rod not only 
ceases to act as a moving force for the reel, but the force due to the weight 



70 BEEP SEA-SOUNDING AND DEEDGIKG. 

of the sinker and rod is automatically transferred to the friction-line, 
because the cross-head, being freed from the bearing-down effort of the 
weight of the sinker and rod, rises and communicates that effort to the 
friction-line. This peculiarity may not appear to give any great advantage 
over the original machine, yet it is a safeguard, and provides a reaction 
against the momentum of the reel at a critical point. Since it results, 
without extra cost, from the action of such parts of the machinery as are 
devised for other, and perhaps more necessary, purposes, it may at least 
be considered an acceptable feature in the working of the apparatus. 

In practice it is found, both with the original Thomson and the Sigs- 
bee machines, that to maintain a rapid rate of paying out the pull upon 
the friction-line (not friction, but pull upon the line) has gradually to be 
reduced froim the time of starting the sounding. This is chiefly due to the 
friction on the submerged wire. On board the "Blake" we would occa- 
sionally, in very deep water, find the cross-head nearly at the top of its 
guides, and the reel controlled by the resistance due to a very light strain 
on the friction-line. In this case we would lose to a considerable extent 
the governing action of the accumulator and the automatically increased 
resistance at the instant of striking bottom. The -remedy was to use a 
friction-line of smaller stuff when sounding in very deep water, or to 
decrease the length of the arc of bearing-surface which the friction-line 
had in its score by making its standing part fast somewhere above the 
bed-board of the machine. The use of a heavier sinker will also serve the 
same purpose. In regard to the size of the friction-line only that part 
which is wrapped in the friction-score is of much moment. 

In a heavy sea, if sounding from the bow, the violence of the vessel's 
motion may cause the reel to "race'' occasionally, notwithstanding the 
governor. This will be understood when it is stated that the "Blake" has 
been known to plunge so quickly as to slack the wire when reeling in by 
steam. To provide against racing in seas exceptionally heavy for the 
work, we used a very simple and completely successful device. While the 
reel was unwinding the wire under the usual frictional control a small 
toggle turned into the friction-line outside of the pulley Y (Figs. I, III, V), 
on the same side of the bed as the friction-score of the reel, was made to 



THE SOUNDING-MACHINE AND ITS USE. 71 

bind with a force of several pounds against tlie pulley, by setting up taut 
on the standing part of the friction-line at the scales X (Fig. I). Thus, 
while the governor was free to automatically increase the friction upon the 
reel as occasion demanded, it was incapable of decreasing it to an amount 
less than that due to the resistance of the toggle against the pulley. 
Stretching of the friction-line will cause the toggle to recede from the 
pulley, and the friction-line may have to be set up afresh at the sfanding 
part several times during a deep cast in very heavy seas; this, however, 
does not necessitate a stoppage of the reel. A close inspection will show 
the toggle on Plate 9. While this device may be dispensed with, even in 
very heavy seas, by the exercise of a little care, its use under such circum- 
stances permits- a more rapid rate of descent. 

When paying out wire, oil or fresh water should be applied freely to 
that part of the friction-line resting in the friction-score. This will give 
smooth work. Water, if used, must be applied frequently; oil not neces- 
sarily so often. 

As soon as the sinker strikes bottom, which is made apparent l^y the 
stoppage of the reel, read the register or the odometer, and, at the same 
time, ship the cranks ©n the axles of the reel. Throw the bight of the fric- 
tion-line out of its score, and, to insure the detaching of the sinker, pay 
out cautiously one or two turns of the wire, if necessary, until the strain 
upon it is eased. Then reel in a few turns slowly and carefully, when the 
distance which the cross-head is borne down along its guides will indicate 
if the sinker be clear. Usually, with a good form of detacher, it drops off 
at once on striking bottom, requiring no actual slacking of the stray-line 
or wire. The exceptions are most likely to occur when paying out slowly 
in strong currents. In paying out extra turns of wire to detach the sinker 
it should be remembered that the wire must not be allowed to coil on bot- 
tom; nor should the stray-line be allowed to foul the rod or sinker on the 
bottom. If a thermometer have been fastened to the stray-line for observ- 
ing the bottom-water temperature, care should be exercised that the sound- 
ing-rod may not drag along the bottom while waiting for the thermometer 
to register. Although we always used steam for reeling in, it was our 
invariable custom first to reel in fifteen or twenty turns by hand before 
connecting with the engine, and with inexperienced supervision at the 



72 DEEP-SEA soundi:ng and deedging- 

machine the last fifteen or twenty turns should also be got in by hand — 
that is, by men working at the cranks. 

If the strain-pulley is to be employed for reeling in, Plate 36 (dotted 
line, Fig. 1) and Plate 11 will show the manner of leading the wire, which 
is as follows : The last or uppermost turn of the wire upon the reel leads 
from the latter six or seven times around the wide score of the strain-pulley, 
"with the hands of a clock" or "with the sun," and thence underneath the 
reel, over the cross-head pulley and into the water. The power for reeling 
in is applied to the strain-pulley, from which the wire is passed to the reel 
with the tension reduced. To keep the parts of the wire from riding over 
each other on the strain-pulley a standard with a roller is interposed, as 
shown on Plates 11 and 36. It is seen that the wire, after coming in over 
the cross-head pulley, passes over a large part of the circumference of the 
coil contained on the drum of the reel. It is thought that this may pos- 
sibly cause the wire to act as a belt to revolve the reel for taking the turns 
from the strain-pulley, but if the arrangement prove insufficient for the 
purpose stated, a loose belt of rope, just long enough to fit, should con- 
nect the friction-score of the reel with the score C (Fig. V, Plate 38) of 
the strain-pulley. The weight alone of a small rope would, doubtless, 
give enough friction for a connecting slip-belt. 

The use of the score D (Fig. V, Plate 38) is to connect the strain- 
pulley with a reeling-engine by a rope belt. Plate 13 shows the two 
connecting belts that have been described. 

When the strain-pulley is not to be used a rope belt maybe taken directly 
from the friction-score of the reel to the V-groove of the reeling-engine. 

KEEPING A TIME-RECORD OF SOUNDINGS. 

It was our custom to keep a record, as shown on Form 1, next page, 
at every sounding taken with wire. This practice is useful in various 
ways. The officer of the deck is thus kept constantly posted as to the 
speed of the machine, and is given experience with regard to its capabili- 
ties; should the register cease to record from any cause the fact is made 
known, and when plotting, if a non-agreement is observed between sound- 
ings on the same or intersecting lines, the means of verifying tlic figures 
relating to the soundings are at hand. 



ji -^:::^ 




> 



THE SOl7NDIN(;-MA CHINE AND ITS USE. 



FOEM 1. 
U. S. COAST SURVEY STEAMER "BLAKE." 







Locality, 


20 miles N. W 


o/So,, 


brerold. Dat 


», Apn 


23,1879. Sounding No. 25. Line, P. P. 


Turns 
Keel 


REELING OUT. 


REELING IN. 




Times. Intervals. 


Times 


j Intervals. 


REMARKS. 
To bt- i.iadf by tl.e Officer of tlie Deck. 


Kegis- 












TEB. 


H. M. 


" 


Jll •■ 


! 


s. II . 


s. 







11 1 21 








1 

12 30 


1 
20 :| 


"55" 


Sinker used, Slml. Weight, 60 lbs. 


100 i' i 22 


34 i! 1 02 


29 


25 


47 


Was sinker detached or recovered ? Dehwlml 


m \: i 23 


25 i 51 


28 


38 


47 


No. of fathoms of stray-line used, 9. 


300 y I 24 j 15 '.\ . 50 


27 


51 : 


49 


No. of turns of wire in use on reel, Ufl58. 


UOO \ 25 1 06 1 51 : [27 


02 


54 


Kind of reel used. Navy steel reel (reduced). 


.500 25 ; 58 ' 52 ; | 26 


08 


54 


■Weight of reel used, mi lbs. 


600 26 52 '54 \\ 25 


14 


59 


Reeled in by Steam (hand or steam?). 


700 27 : 46 54 \'. 24 


15 1 


01 


Reeled in iirst l.i turns by hand. 


800 28 : 43 57 ' 23 


14 1 


04 


Reeled in last V, turns by hand. 


• .900 29 43 1 00 : 22 


10 1 


03 


Wind N. E. to N. N. E. Force 1 to .}. 


1000 30 41 , 58 : ■ t 21 


07 1 


07 


State of the sea. Light swell from E. N. E. 


1100 31 4:3 1 ; 02 , 20 


00 1 


10 


Vessel rolling. Easili/. 


1200 ! 


32 i 46 : 1 i 03 i; 18 


50 1 


10 


Vessel i.it.-hiny-. Easily. 


1300 


33 48 1 02 f ' 17 


40 1 


13 


Modified Belkmq} rod loith Sigshee detacher used. 


WO 


34 : 54 1 1 06 j 16 


27 1 


18 


Reeled in sloidy because the aire had seen much prerwu 


mo 


36 ; 01 ;^ 1 1 07 1 . 15 


09 1 1 


18 


service. 


1600 : 


37 09 : 1 


08 |i 13 


51 ,| I 


21 


Thermometer and water-cup on the dray-line. 


i700 i 


38 15 ; 1 


06 jj 12 


30 i 1 


23 


LOSSES OR CASUALTIES. 


1800 ji 


39 1 26 '; 1 


11 !; : 11 


07 i 1 


24 


Nmie. 


1900 \\ 


40 35 :[ 1 


09 ; ; 09 


43 1 


25 




WOO ! 


41 [ 48 i 1 


13 ji 08 


18 J 1 


25 




SlOO ! 

2200 i 


43 02 ; 1 

44 11 ; 1 


14 j ' 06 

09 ij 05 


53 ; 1 

16 :| 1 


37 
34 




mo 


45 24 ; 1 


13 I : 03 


42 ' 1 


38 


Reading of Register 2, 76-5 turns. 


mo ■ 


46 \ 38 ! 1 


14 ' 02 


04 ; 1 


31 


Correction for stray-line 6 


2500 


47 53 'j 1 


15 1 12 ' 00 


33 [j 1 


66 


Correction for turns of wire. 158 


2600 1 


49 i 08 1 


15 


58 


37 1 


53 




S700 
2765 


11 


50 ! 24 J 1 

51 17 i 


16 
53 


11 


56 
55 


44 
45 




59 


Correct Oeptn 9,929 futhoms 


2900 


















SOOO 


- 








.j 








Totals. 


! ^ 29 


45 






34 


35 





Signature of Officer of the Deck :_ 
Signature of the Recorder: 



The al)( 
the deepe 



V Commander Bartlett to show tlie 
t for which it had heeii used up tf) that time. The figui 



ich is verj' slow for the "Blake, 
is shown to have been l-" 01^. and for reeling in 1"' 11-. 
revolving at the rate of one hundred turn,? (about one bund 
in from these two soundings it appears that the vessel ^v: 
the wire had something to do with it, or, since these were 
was decided to be cautious. The "Blake" being an econo 
ing day and night with different officers in charge of tlie n 
make quick time is rarely attempted. 
10 D S 



rorking of the Sigshee machine in 
•epresent fair work, excepting the 



of paying out, per one hundred fathoi 
The sinker touched bottom when the reel was 
ed and twelve fathoms) in 1"> 16^ While reeling 
s not steamed ahead. Probably the weakness of 
;he deepest casts ever made fi-om the "Blake," it 
ii<'al vessel in the expenditure of coal, and work- 
achine, to take much risk with the wire in order to 



74 



DEEP-SEA SOUNDING AND DREDGING. 





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THE SOUNDING-MACHINE AND ITS USE. 



15 



HAULING BACK A LEAD SINKER. 



After getting an accumulator the greater number of our casts no deeper 
than eight hundred or 1,000 fathoms were taken with the thirty-four-pound 
sinker, which we always hauled back by steam. The accumulator, acting 
as a dynamometer, will direct the judgment in regard to the safety of haul- 
ing back, but in respect to the advisability of the measure, economy of 
time and money will have much influence. We thought the small saving 
of shot-sinkers no object in depths greater than 1,000 or 1,200 fathoms, for 
the rate of paying out with a light lead then became so slow that the loss of 
time in favorable working weather was the more important consideration. 
In regard to the safety of hauling back the lead, the state of the sea made 
but little difference with us in a depth of 1,000 fathoms. Sometimes the 
accumulator cross-head would traverse its full range while we were hauling 
back in a heavy sea. The following shows work with the lead: . 

U. S. COAST SURVEY STEAMER '-BLAKE." 

Locality, Off Grenada. Date, March S, 1879. Sounding No. 37. Line K. 



Turns 


KEELING OUT. 


KEELING IN. 




Keel 


















Times. 




Intervals. 


Times 




Intervals. 




















To be made by the Officer of the Deck. 


TEH. 




M. 


s. 


=■ 


M. 


s. 


M. 


- 







4 20 


4a 






4 


43 


30 


1 


00 


Sinker used. Lead. Weight, 34 lbs. 


100 


21 


42 




57 




42 


30 




46 


Was sinker detached or recovered ? Recovered. 


200 
SOO 


22 
23 


35 


1 


53 
00 




41 
41 


44 
01 




43 
49 


No. of fathoms of stray-line used, 9. 
No. of turns of wire in use on reel, 4,387. 


UOO 


24 


30 




55 




40 


12 




50 


Kind of reel used, Navy steel (reduced). 


500 
WO 


25 
26 


32 
40 




02 
08 




39 


22 
18 


1 
1 


04 
03 


Weight of reel used, 125 lbs. 

Keeled in by Steam (hand or steam V). 


700 


27 


50 




10 




37 


15 


1 : 13 


Reeled in first 8 turns by hand. 


800 


29 


25 




35 


36 


02 


1 1 03 


Reeled in last 15 turns by hand. 


875 


4 30 


35 


1 ^ 


10 


4 34 


59 


1 


Wind,Eaa<. Force, 2. 




r 




1 9 


50 


1 




* 31 


State of the sea. Moderate. 












Vessel rolling, 1 ^^ 
Vessel pitching, j 










875 turns. 
6 


Correction for stray-li 








f wire 








LOSSES OK CASUALTIES. 



































The times are fair, but would be slow for work with a shot-sinker. With the vessel quiet, aud particu- 
larly when sounding Avith shot, considerable time is sometimes gained in deep soundings by allowing the reel to 
pay off the wire very rapidly, under less resistance than is called for by the rule, until the sinker has arrived 
within several hundred fathoms of the bottom, when the resistance is increased to the safety point. To attempt 
this, one must feel sure that he can foretell the depth approximately. 



76 



DEEP-SEA SOUNDIi^G AND DEEDGING. 



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III 

111 



THE SOUNDING-MACHINE AND ITS USE. 77 

When a thirty-four-pound lead has reached a depth of 1,000 fathoms 
the weight of the submerged wire is twelve pounds, and if the resistance upon 
the reel is seventeen pounds — five pounds surplus — the effective weight of 
the sinker, on which we have to depend for rapid work, is but seventeen 
pounds; with a sixty-pound shot-sinker under like conditions the effective 
weight is Ibrty-three pounds, a positive advantage of twenty-six pounds; 
with the seventy-two-pound sinker, sometimes employed, the effective 
weight is fifty-five pounds, and the gain on the lead thirty-eight pounds 
under the conditions cited. In a heavy sea it is advisable, in order to 
guard against the wire flying from the drum, to keep the submerged wire 
under stronger tension than is usual in a smooth sea. This is done by 
placing a greater resistance upon the reel than is called for by the rule, but 
for every pound of surplus resistance thus added the effective weight of 
the sinker is reduced by one pound, a loss which is obviously more of a 
disadvantage with the thirty-four-pound lead than with the sixty-pound 
shot. 

THE CLAMP AND ITS USE. 

Sometimes it becomes necessary to clamp the wire at the machine 
during the operation of sounding; for instance, a kink or a defective splice 
appears, or the wire flies from the reel, requiring a manipulation of the 
wire that is possible only when it is slack. Fig. XIII, Plate 36, shows a 
clamp made to fit into the fairleader on the forward part of the bed-board of 
the sounding-machine; it consists of the following: Two pieces, or chocks, 
of lignum-vitae a a, the right and left hand screw h; and the guide bolts c c, 
set rigidly into one piece of the lignum-vitae, and sliding freely in cylin- 
drical holes in the other. For clamping, the wire being slipped into place 
as shown at d, the clamp is lowered to the fairleader and the wooden 
parts firmly set up against the wire by means of the screw; or the clamp 
may be clapped on the wire inboard of the cross-head pulley and lashed 
somewhere near the bottom of the guides, on the bed-board, in which case 
the submerged wire and weights will ride from the accumulator. A small 
box-like arrangement should be fitted to the bed-board of the sounding- 
machine for containing the clamp, where the latter may be in readiness for 



78 DEEP-SEA SOUNDING AND DEEDGING. 

instant use. Marline or rope-yarn, though unhandy, may be used to 
stopper the wire. 

STATIONS AT THE SOUNDING-MACHINE. 

When sounding, the officer of the deck always stood forward of the 
machine so that he need never turn his back on any point requiring atten- 
tion. In heavy seas it was the custom of the officer of the deck to keep 
the left hand on the friction-line just inboard of the reel (near the scales 
X, Plate 36) , where any unusual slacking of the friction-line could be felt 
at once. 

Three men were stationed at the sounding-machine : one out on the 
accommodation-grating to get over the rod and sinker, to fasten on the 
thermometer and water-cups, to guide the wire and report the direction in 
which it tended from time to time; one at the forward side of the machine 
to watch the register, to apply the alkaline mixture, to guide the wire to 
the reel, and to attend the hand-cranks; and another at the after side of 
the machine, to assist with the sinkers, thermometer, and water-cups, to 
attend the hauling part of the friction-line in paying out, to attend the 
throttle of the reeling-engine when reeling in, and to work at the hand- 
cranks when necessary. 

ACCIDENTS. 

Ttie Friction-une j»«r*s.— Stop the reel by seizing it with the hands about 
the flanges of the drum; but not by throwing the pawl into the ratchet- 
wheel, against which it is necessary to caution untrained men. 

Tlie Wire Fouls on the Vessel's Bottotn in Paying Out. — It Is liot likely tO fOUl 

in this way excepting by the catching of a splice. Ship the cranks and reel in 
one or two fathoms, or until the splice appears; if the wire still tend under 
the bottom, endeavor to clear it by backing or steaming ahead, by shifting 
the helm, or perhaps with the sails. When the wire is allowed to pay out 
under the vessel, across the keel, it is impossible to know its angle from a 
vertical direction, and the depth of the sounding will be in doubt. 

The TVire Fouls on the Vessel's Bottom tchen IteeUng In. — 111 thiS CaSC, if the 

power for reeling in comes from an engine, there is little probability of the 
wire holding together; but should the wire foul and not part, pay out a 




itrH 



THE SOUNDING-MACHIKE AND ITS USE. 79 

few fathoms, and then if it does not swing clear resort to manoeuvring, as 
in the preceding case. If steaming ahead while reeling in, this accident 
will probably never happen, but most vessels do not follow that practice. 
Since it is not necessary to keep the wire strictly vertical while reeling in 
there is but little excuse for this mishap excepting on very dark nights, or 
when a shift of wind has occurred during the operation of sounding, 

A nidge Appears in the Coil of Wire when Paying Out. This results WheU the 

wire has been carelessly wound in reeling back from a previous sounding. 
If the ridge begin to slip, as it probably will, so as to slack some of the 
turns, stop the reel, clamp the wire inboard of the cross-head pulley and 
cut it at the reel, letting the submerged wire and weights ride from the 
accumulator ; or reel back, if possible. Wind wire from the working 
reel to a spare reel until the ridge is reduced ; then wind back again to 
the working reel, cutting out all defective parts. When a ridge once 
begins to show slack turns, a persistence in paying out will cause the wire 
upon the reel to kink in many places. Although this case happened to 
us but once, I give the above from my own experience combined with 
that of others. The formation of a ridge is so much the result of care- 
lessness that it is stretching a point to call it an accident. 

POSITION OF THE SOUNDING-MACHINE: LAYING THE VESSEL FOR SOUNDING. 

The proper place to set up the sounding-machine depends somewhat 
on the character and qualities of the vessel engaged in the work. 

In general terms the jerky and oftentimes rapid motion of pitching, 
particularly in a short vessel, which would be felt to its fullest extent at 
the bow and stern, causes more trouble than the smoother and more regu- 
lar rolling motion, the maximum effect of which is at the gangways ; also, 
since the vessel is laid head or stern to wind for sounding, the pitching 
will generally be in excess of the rolling, considered in relation to the 
disturbing influence on the action of the sounding-machine. 

Captain Belknap in his Pacific work sounded from the gangway of the 
"Tuscarora," and generally, I believe, laid the vessel with her stern to 
wind and sea. Most other naval officers who have had charge of sounding 
operations since then have retained the gangway position for the machine. 



80 DEEP-SEA SOUNDING AND DREDGING. 

but just how they have laid the vessel there is no available means for 
ascertaining. In sounding from that part of the vessel there is a diffi- 
culty in manoeuvring to keep the wire vertical; in fact, decided failures 
sometimes result in this particular, as is shown by records to which I 
have had access. In a man-of-war, however, it is an important point to 
have the machine under the eye of the commanding officer, a convenience 
afforded by the gangway position. 

From the "Blake," under my command, we always sounded from the 
port bow, as far forward as the machine could be set up (Plate 7; and 
G, Figs. 1 and 2, Plate 29) , consequently we suffered the full effect of the 
pitching motion. For sounding, the vessel was laid head to wind, with 
mainsail set and the main boom amidships. Thus laid, the usual tend- 
ency of the vessel was to drift with the wind, drawing the wire ahead rather 
than drifting over it, which is a point of great importance for night-work. 
The rapidity with which the "Blake" would swing her stern to port in 
backing under ordinary circumstances — in the extent of which character- 
istic she was exceptional — suggested sounding from the port bow. If the 
wire tended under the bottom of the vessel we had, usually, only to give 
the main engine a few turns back to bring it clear. If it occurred while 
paying out, the speed of the reel was checked until the wire was again 
vertical, and thus no cast was taken from the "Blake" which was not to 
all appearances "up and down." All things considered, sounding from the 
bow is probably most favorable to accurate results, and also the most 
convenient when it is intended to reel in the wire vertically. 

When the latest form of the Sigsbee machine was put on board, to be 
used in charge of Commander Bartlett, another position from which to 
sound became necessary to admit of reeling in while steaming ahead, an 
operation for the performance of which it has been shown the new machine 
is fitted. Accordingly, the position selected was just forward of the port 
fore-rigging (Plates 13, 14, 15; and G, Fig. 3, Plate 29). Here nearly all 
the advantage of the former position is retained, and there is a straight lead 
aft for hauling in the wire as it trails astern while the vessel has headway. 
Beports from the vessel assert the convenience of the new position. 

In sounding from the stern there would be the danger of fouling the 



THE SOUNDING-MACHINE AND ITS USE. 81 

wire by drifting over it, and the risk of fouling with the propeller in a 
screw vessel, unless the vessel were laid stern to wind; particularly would 
the latter be liable to happen at night, when it is difficult to see the wire 
after it has left the reel. The chief advantage to be derived from the posi- 
tion would be facility for reeling in and steaming ahead at the same time. 
On board a vessel having large running expenses, and of which nothing 
but depth and bottom-soil specimens were expected in the way of results, 
the stern would doubtless be the best place from which to sound. If strict 
accuracy in regard to depth were not required, so much the more reason 
for choosing the stern, for the wire then might be payed out slightly in- 
clined from the vertical, tending astern, to keep it clear of the propeller, 
and any risk to the wire likely to ensue would be well taken in view of the 
saving effected by sending the vessel ahead on her course with the least 
possible delay. 

With regard to the minor considerations which might be taken into 
account when selecting a position for the sounding-machine, such, for 
instance, as cleanliness, noise, deck space, appearances, proximity to the 
engine-room bells and the helm, the whipping about of running rigging, 
&c., no discussion is necessary. 

REELING IN WHILE STEAMING AHEAD. 

The economy of making headway on the projected course while the 
wire is being reeled in from deep casts is apparent. Discussion is not nec- 
essary to demonstrate that it can be done, for it has long been the practice 
on board at least one of the English cable steamships. The present posi- 
tion of the "Blake's" sounding-machine (Plates 13, 14, 15) is not the best 
that could be selected for this special purpose, but the machine itself is 
suited to any angle of direction which the wire would be allowed to take.* 

The table here given shows the results of an experiment in towing 
wire from the "Blake" in 1877. The figures are chiefly valuable for show- 

* It is tfi be regretted that the vahie of the new position in this respect has not been put to a test, owing 
to the dredging, temperature, and water-specimen work which followed a great number of the casts made by tlie 
"Blake" on her recent cruise, requiring her continuance at the sounding station for some time after the cast. 
When Commander Bartlett had made all arrangements for securing important data in connection with this and 
other matters suitable for publication in tliis book, it became necessary to order the vessel north. 
11 DS 



82 



DEEP-SEA SOUNDING AND DREDGING. 



ing the small effect of the oscillations of the vessel in varying the strain 
upon the wire. The maximum strain nowhere exceeds the steady strain 
by more than five pounds, while a difference as great as eighty pounds has 
been known when reeling in with the wire vertical. It is to be regretted 
that the experiment was not repeated without the lead. 

EXPERIMENT IN TOWING SOUNDING- WIRE FROM THE "BLAKE." 





1 


Strain 


on the 


vh-ehi 


|c| 








^^ 


pounds, sh 


owing 


o^ 










the effect of the 


■Stg 






§ 


^-jj 


roll 


ingaud 


pitch- 


£§ 






2 




iug 


of the 


vessel. 


•?? 








II 








II 


Remarks. 


Remarks. 


E 

rC 


■ ^ 


>. 


"i 






1- 


1 


J 


1 


^^ 






C) 


8.3 


41 


45 


49 


" 42. 8 




During the operation the vessel was steam- 


n 


5.3 


30 


34 


37 


1 07.0 




ing in the trough of a moderately heavy 


100 


7.3 


41 


45 


49 


48.7 




sea, and was rolling and pitching consid- 


100 


6.3 


39 


41 


43 


56.4 




erably, sometimes even heavily. In the 


250 


7.0 


45 


50 


54 


50.8 




first column 8 fathoms of stray-line are 


250 


4.0 


35 


42 


47 


1 28.8 




included in the given length of wire out, 


500 


6.5 


52 


60 


65 


54.7 




and the strain in every case is that due to 


500 


3.6 


37 


43 


44 


1 38.7 




the pull of wire, lead, and 8 fathoms of 


750 


7.0 


67 


69 


72 


50.8 




stray-line. The lead used was 18 inches 


750 


3.6 


43 


45 


46 


1 38.7 




long, of the ordinary commercial pattern. 


1,000 


7.0 


75 


78 


81 


50.8 


PitcMngheavUy. 


fitted with a Stellwagen specimen-cup. 


1,000 


5.5 


68 


70 


73 


1 04.6 




the whole weighing 34 pounds. 


1,250 


7.0 


91 


93 


96 


50.8 


Repeated. 


Having paid out 2,000 fathoms, we com- 


1,250 


4.7 


70 


72 


74 


1 15.6 




menced to reel in hy steam, the vessel's 


1,500 


6.7 


100 


102 


103 


53.0 




speed heing 6.6 knots. 100 fathoms came 


1,500 


4.5 


74 


76 


77 


1 19.0 




upon the reel in 3'" lO'* ; but on attempt- 


1,750 


6.5 


105 


108 


110 


54.7 




ing to reel in the second 100 fathoms at 


1,750 


3.6 


75 


77 


78 


1 38.7 




the rate of about 3™, the vessel going 


2,000 


7.3 


125 


126 


128 


48.7 




at the same speed as before, the wire 


2,000 


3.7 


75 


78 


79 


1 36.0 




parted— a fair break, and not in a splice. 



It is seen that when the wire parted it was being hauled through the 
water, with the lead and stray-line attached, at a speed of 8.57 knots per. 
hour or one hundred and forty-four and three-fourths fathoms per minute, 
which is at the rate of one hundred fathoms in 41.4 seconds. When there 
were 2,000 fathoms out, and the vessel was making a speed of 7.3 knots, 
the wire, line, and lead were being towed at the rate of one hundred fath- 
oms in 48.7 seconds, yet the maximum strain upon the wire was only one 
hundred and twenty-eight pounds, of which about forty-five pounds were 
due to the stray-line and sinker. 



1 




THE SOUNDING-MACHINE AND ITS USE. 83 

Although the table shows that an accumulator, as such, is not required 
when reeling in while steaming ahead, yet as a dynamometer it would 
perform important service. The dynamometer, by showing the strain upon 
the wire at each instant, would permit a safe and rapid rate of reeling in 
without a resort to time-interval checks involving a considerable calcula- 
tion, or to the use of prepared tables; and should sea-weed or other mat- 
ter held in suspension below the surface of the water foul with the lead or 
sounding-rod the fact would be made known at once by the dynamometer. 

In the performance of the operation under discussion the main object 
would be to get the vessel as far ahead on her course as possible; while the 
time consumed in reeling in would be of secondary importance, and need 
be limited only by the time required to reach the next sounding station. 

If in the time that otherwise would be occupied by a vessel in reeling 
in with the wire vertical, she can succeed in steaming ahead on her course, 
however slowly, and at the expiration of that interval of time can start 
ahead at full speed with safety to the wire which is towing astern, she will 
obviously have gained by the method of steaming ahead while towing the 
wire. This suggests the following as being probably a good plan for 
general work in this particular. 

Decide on the working strain to which it will be safe to submit the • 
wire that is in use. After bottom has been reached send the vessel ahead 
at a speed which will admit of a slow rate of reeling in without exceed- 
ing the accepted working strain. Constantly keep this strain upon the 
wire — first, by gradually increasing the speed of the vessel while main- 
taining the initial rate of reeling in, and then, after the vessel has reached 
full speed, by gradually increasing the rate of reeling in. 

I have known several cases in which sharks have parted the wire by 
seizing the bright instruments attached to the stray-line. Certainly below 
five hundred fathoms, and probably below one hundred, this remote dan- 
ger will cease. When the wire is towing, the chances of being thus an- 
noyed are greater than when reeled in vertically, and it is suggested that 
the outside of the instruments might be painted a dead black or a dark 
lead-color to make them less alluring to sharks. 



84 DEEP-SEA SOUNDING AND DEEDGING. 

DESCRIPTION OF A NEW STEEL REEL: REMARKS ON CRUSHING FORCE. 

(Plate 16.) 

A cast-steer drum, with the two outer flanges A, A, and the three 
inner flanges B, B, B, the thickness of metal being one-eighth of an inch 
throughout, excepting at the angles G, C, where it is somewhat thicker. 

The one-eighth-inch sheet-steel side-plates D, D, set up to the drum 
by the half-inch steel socket-bolts E, E, E, &c., which pass through the 
inside flanges B, B, B, and are secured with the nuts F, F, &c. The drum 
should have as nearly as possible a perfect contact with the side plates. 

The cast-steel friction-ring, with score G, secured to the steel bolts 
E, E, E, &c., by the iron screws H, H, H, &c. 

The wrought-iron three-eighths-inch riveted socket-bolts I, I, I, &c. 

The cast-iron center-block J, to which the steel side-plates are secured 
by the three-eighths-inch wrought-iron riveted bolts K, K, K, &c. 

The steel axle L, to be fitted with cast-iron or steel ratchet-wheel and 
a steel worm, as shown on Plates 36, 37, 38. 

The wrought-iron or steel key M. 

The steel w^ashers N, N, N, &c., to give additional strength to the out- 
side flanges of the drum at the points C, C. 

No brass is to be employed in the manufacture. 

This reel weighs about eighty-one pounds without the axle ratchet- 
wheel and worm, and about ninety-five pounds when fully equipped. 

The drum should exactly accommodate one fathom of the sounding- 
wire at a single turn. The diameter of a circle having a circumference 
of one fathom is 22.918 inches, and this being decreased by 0,028 inch, 
thickness of the wire, gives as the diameter of the drum 22.89 inches. 

All the joints sJwuldhave, as nearly as possible, a perfect ^t, that the reel 
may he very strong as a whole. 

A reel made after the drawings shown on Plate 16 was put on board 
the "Blake" when the vessel had come under the command of Commander 
Bartlett. The view of this reel from which Plate 17 was made was ob- 
tained during a rain and the plate is therefore not very successful. 

Under the direction of Commander Bartlett, Lieutenant Wallis sub- 



U. S. COAST SURVEY. 



DEEP SEA SOUNDING AND DREDGING. 




Ftq. 1 



1 , 1 ,1 , 1 , 1, I .I , I , I , I , l„iJ 
Scale of Inches 



Ft^.2 



NEW STKEL REEL POR SOU-NDTNG AVITH WIRE. DEVISED BY LIEUT COMDB. CTl.SIGSBEE, U. S.N..ASSIST COAST SURVEY 



THE SOUNDING-MACHINE AND ITS USE. 85 

jected the new steel reel to the following experimental test: 3,868 turns 
(4,025 fathoms) of sounding-wire was wrapped upon it under an invariable 
tension of fifty pounds. If every part of the reel and the enwrapped wire 
remained rigid throughout, then the reel must have sustained a crushing 

force of 172if|^ tons; (^ 2940 )• Granges were carefully applied 

to various parts of the reel during the experiment and on its completion. 
After the whole 4,025 fathoms had been reeled up, the outer flanges A, A 
of the drum were found by the gauge to have retained the same distance 
from each other which they had at first, and no part of the reel had suffered 
any change that could be detected, excepting at the seam, on either side, 
where the side-plates are set up against the under side of the drum ; here 
the outside face of the flange and the outside face of the side-plate — the 
vertical faces — were just visibly separated, whereas at first they had been 
in the same plane. The bearing contact of the joint, however, was perfect, 
and the side-plates simply gave the appearance of having been forced 
outward very slightly and evenly all around the seam. Care was taken 
to detect any excentricity, but the circularity, and the concentric relation, 
of the parts remained, apparently, perfect. The ultimate strength of the 
reel had not been reached. Should greater strength be required, the mid- 
dle inner flange might be made deeper. 

It is remarkable that the galvanized sheet-iron reel and the Navy brass 
reel should have resisted, even to the extent realized, the accumulated force 
which apparently has been brought upon them when reeling back from deep- 
sea casts. The explanation must, I think, be sought, first, in the elasticity 
of the reel and its coil of wire under severe compression; and, secondly, in 
the expansion upon the reel,* in most cases, of a great deal of the wire that 
had been submerged — an action due to its change from a lower to a higher 
temperature soon after leaving the water. While it is evident that the 
turns of wire, under certain relative thermal conditions of the air and water, 
may contract upon the reel on leaving the water, it is nevertheless true that 
in nearly all of the casts yet taken by the Navy and by the Coast Survey 
the reverse must have been the case. 

In a paper lately brought to my notice it is assumed that the wire, 



86 DEEP-SEA SOUNDING AND DEEDGING. 

in a special case mentioned — depth 1,900 fathoms — must have contracted 
soon after leaving the water, causing a great accumulated force upon a 
reel which was crushed, the reason assigned for the assumption being 
that the air was of several degrees lower temperature than the water. 
Only the temperature of the surface-water was considered in connection 
with the air temperature — air, 60°, surface-water, 63°, Fahrenheit. 

From records of serial temperature work previously done near the 
locality cited, I get the following relation of temperatures : Fahrenheit 
scale — air, 60°; water — surface, 59°; twenty fathoms, 57°; one hundred 
fathoms, 46°; one hundred and fifty fathoms, 44°; bottom, 1,900 fathoms, 
35°. A few degrees of daily change in the temperature of the air or the 
surface-water will effect but little change in the water temperatures below 
ten or twenty fathoms. 

From the figures given it is at once seen that in the case discussed by 
the paper in question the wire must have expanded on the reel. Every 
part of the submerged wire, excepting the upper one hundred fathoms, must 
have left the depth of one hundred fathoms, in the ascent, at a temperature 
certainly no higher than 46°, and in less than one minute and thirty sec- 
onds thereafter, as shown by the records, it was resting upon the reel. 

REELING-ENGINE AND ACCESSORIES FOR SOUNDING PURPOSES. 

During my first two years on board the "Blake" we reeled in the 
wire by means of a long rope belt taken over the friction-score of the reel 
and led through blocks to a large hoisting-engine fastened to the deck abaft 
Ihe pilot-house, in the same place afterwards occupied by the engine shown 
on Plates 30, 31, 33, and others. Plate 29 (Figs. 1 and 2) will give a good 
idea of the length of belting required, G being the sounding-machine and 
A the hoisting-engine. Afterwards a Snyder horizontal engine was placed 
upon the bed-board of the experimental machine, as shown on Plate 7; it 
is also located on Plate 29 (Figs. 1 and 2), G and H indicating the sound- 
ing-machine and reeling-engine, respectively. With this we have reeled in 
as fast as one hundred turns — more than one hundred fathoms — in twenty - 
six seconds, and a speed of one hundred turns in forty-five seconds was a 
very common occurrence. The connection between the reel and the small 




> 



m 



W 



THE SOUNDENG-MACHINE AND ITS USE. 87 

engine was made by a rope belt, for the reception of which the engine 
was provided with a V-groove fly-wheel. For tightening the belt I 
designed a pair of tightening-pulleys, which are shown imperfectly on 
Plates 7, 13, and 14. This arrangement may be described as follows: A 
standard, to the lower part of which a stud-bolt is fastened to form a pin or 
axle on which the lower pulley may revolve freely. The upper part of the 
standard is squared, and sliding freely upon it is a collar, to which a second 
stud-bolt is fastened to form a pin or axle on which the upper pulley may 
revolve freely. The upper part of the sliding collar is shaped so as to be 
capable of holding annular lead weights. The lower part of the endless 
belt is led over the top of the lower or stationary pulley, and the upper 
part under the upper or sliding pulley. Any desired degree of tightening 
may be given the belt by adding weights to the sliding collar.* 

When the latest form of the Sigsbee sounding-machine was put on 
board the "Blake" it was not convenient to place the little reeling-engine 
upon the bed-board while the strain-pulley was retained. Accordingly, 
the engine was placed as shown at H, Fig. 3, Plate 29 — G being the new 
sounding-machine. (See also Plates 13, 14.) 

Plate 18 shows a small incline reeling-engine, designed at my request 
by Mr. Earle G. Bacon, of Messrs. Gopeland & Bacon, New York, and 
intended to occupy the place upon the bed-board of the sounding-machine 
at present assigned to the strain-pulley. The cylinder is of Mr. Bacon's 
patent trunk pattern, of five and a half inches bore. The standards are 
joined at the bottom, being cast in one piece, and are cored out in order to 
make them as light as strength will permit. The V-groove pulley, as 
shown, might be dispensed with, and the fly-wheel given three scores, cor- 
responding to those on the strain-pulley .f On board a vessel permanently 
engaged in deep-sea sounding such an engine would doubtless be connected 
with the boilers by piping; but for use on board vessels not likely to 
retain the sounding-machine as a fixture, rubber steam-hose might be used 
for the steam and exhaust pipes. In 1879 Mr. Bacon offered the following 



* The tighteniiig-pulley designed for the new machines, now being made for the Navy and for the Coast 
and Geodetic Survey, is an improvement on the form described. April, 1880. 

t At my request Mr. Bacon has changed the design somewhat, placing the cylinder between the standards, 
with its axis vertical. The size of the bed- plate is eighteen inches by ten and a half inches. April, 1880. 



88 DEEP-SEA SOUNDmG AND DEEDGING. 

prices : For the engine complete, without connecting hose or piping, $225 ; 
for rubber steam-hose, three-quarter-inch inside diameter, five-ply, and 
served with marline, fifty cents per foot ; for rubber exhaust-hose, one 
inch inside diameter, three-ply, and served with marline, fifty cents per 
foot; couphngs, $5 per set. The " Blake's" reeling-engine was worked with 
a pressure of steam ranging from sixty to seventy-five pounds, for whi.ch 
the above-mentioned hose is adapted. The New York Rubber Belting 
Company advertise various grades of rubber steam-hose. 



r>EEP-SEA SOUNDING AND DREDGING 
U. S. COAST SURVEY 



PLAN OF PATENT TRUNK KEELING ENGINE FOTl THE SIGSB£E SOUNDING 
MACHINE -TO OCCUPY" THE PLACE ON THE BED BOAUD AT PRESENT AS- 
SIGNED TO THE STRAIN PULLEY. SHOULD THE LATTER NOT BE REQUIRED 
-DESIGNED BY MR.EARLE C.BACON OF MESSRS. C OPELAND AND BACON, N.Y 





Scale of Indies 



CHAPTEK lY. 

WATER SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS; 
APPARATUS AND METHODS. 

DISPOSITION OF WATER AND SOIL SPECIMENS. 

The specimens of bottom soil or material obtained by the "Blake," 
during her sounding operations, were preserved in glass bottles which were 
simple cylindrical tubes closed at one end' in the manufacture, about two 
and a half inches long and three-fourths of an inch in diameter, resembling 
a small plain beaker-glass, or the cylindrical part of a test-tube. Bottles 
of this kind are a commercial article, and may be obtained, I presume, in 
any large city. The wide, unobstructed mouth, which is a convenience 
both for inserting and extracting the specimen, should be closed with a 
flat selected cork. 

The glass bottle for the preservation of water specimens was of a 
commercial pattern, having a very small neck and mouth, to close which 
we used a long smooth cork. Its capacity was eight ounces. 

As an additional precaution, the corks of all bottles containing speci- 
mens were well waxed. In this state, and labeled with the forms shown 
on the next page, the specimens were sent to the office at Washington on 
the completion of each season's work. 

No attempt to analyze water specimens was ever made on board the 
"Blake." Shortly before Professor Agassiz joined us for the dredging 
operations he had procured apparatus with a view of doing something in 
the way of gas analysis, but he afterwards decided that the proper facilities 
were not to be had on board the vessel. He suggested, as a plan for the 
future, that a properly furnished station be established on shore, convenient 
to some deep-sea basin, whence water specimens might be delivered to the 

12 D S 89 



90 



DEEP-SEA SOUNDING AND DEEDGING. 



station by the quick runs of a steamer detailed for the purpose. With a 
station at Tortugas, for instance, the "Blake" could deliver a specimen 
from 2,(X)0 fathoms within twelve hours after its reception on board. 



U. S. COAST AND GEODETIC SURVEY, 

Carlile p. Pattersox, Superintendent. 



Steamer "BLAKE," 

, U.S.N., Commanding. 



, 18 



WATER SPECIMEN. 

Locality .- . 

Date : 

Lat N., Long W. 

No. of specimen , Line 

With what apparatus obtained: 



Depth of sounding ._ Fms. 

Depth of specimen: Fms. 

Specific gravity at 

temperature of Fahr. 

n the serial 



U. S. COAST m GEODETIC SURVEY, 

Steamer " BLAKE." 

Locality : 

Date: , 18 . 

Lat...^ N., Long W. 

No. of specimen , Line 

DeptTi: Fms. 

Character of specimen: 

With what apparatus obtained : 



REMARKS ON WATER-CUPS, WITH SPECIAL REFERENCE TO THE SIGSREE WATER-CUP. 

Water-cup or water-bottle is the name generally applied to the instru- 
ment by means of which sub-surface water specimens are obtained. The 
work required of the cup or bottle, at any cast, is to bring a specimen from 
the greatest depth which the instrument reaches. Nearly all kinds of 
water-cups are provided with valves which are kept open by the resistance 
of the water during the descent, permitting a current of water through the 
cup, and which, on the ascent, are closed by their own weight or by the 
resistance of the water, thus preventing a reverse current from ejecting 
the inclosed specimen. With the exception of the Sigsbee water-cup, 
shortly to be described, there is no instrument known to me with the use 



U. S. COAST SURVEY 



DEEP- SEA SOUNDING AND DREDGING. 




WATER SPECmEN CUP FOR GETTING A SINGLE SPECIMEN AT EACH HAUL; INDEPENDENT POPPET VALVES: 
USED IN THE COAST SURVEY FOR A NUMBER OF YEARS. 



SPECIMENS, DENSITIES, TEMPERAT[JRES, AND CUREENTS. 91 

of which, collectively, unimpaired specimens may be secured from more 
than one depth at a single cast. 

Leaving the Sigsbee cup out of consideration, the water-cups in gen- 
eral use may be divided into two classes — viz, free-valve and lock-valve 
cups. In the former, the valves are free to act during all stages of the 
cast, but the valves of the latter fall and lock- immediately at the first 
ascending movement through the water. In order to use water-cups 
collectively it is necessary to make stoppages for the purpose of clamping 
the successive cups to the rope during the operation of paying-out; and 
afterwards, when hauling back, a separate stoppage must be made to remove 
each cup as it comes to the surface. The rising and falling of the ship, 
which imparts a corresponding movement to the submerged water-cups, 
must be accepted as a condition attendant on the work ; hence all free- 
valve cups are liable to empty their contents at any stoppage on the ascent, 
and lock-valve cups may have their valves closed and locked at the first 
stoppage during the operation of paying out. 

A short time before he was detached, my predecessor in command of 
the "Blake" had been directed by the Superintendent of the Coast and 
Geodetic Survey to give special attention to the collection of water speci- 
mens from serial depths at various stations in the Gulf of Mexico, particu- 
larly off the mouth of the Mississippi River. The great delay on our lines 
of soundings which would result from the use of ordinary water-cups to the 
extent demanded by our instructions was at once apparent. The only form 
of cup that had previously been supplied to the "Blake" was of the kind 
shown on Plate 19. This had independent poppet-valves, and therefore 
belonged to the free-valve class. To meet this exigency in our work it 
appeared that some form of lock-valve cup should be designed, the use of 
which, collectively, would obviate the necessity of multiplying the casts 
for each station at which water specimens were to be obtained. It was an 
indispensable requisite that the proper action of the valves of such cups 
should be independent of the oscillations of the ship; that the valves 
should be free to open during the whole period of paying out, and that 
they should be kept closed or locked from the time of beginning the ascent. 
Soon after joining the "Blake" I devised a cup which in its working seemed 



92 DEEP-SEA SOUKDING ANB DEEDGING. 

to satisfy these conditions. This cup was improved from time to time, and 
is herein shown in its latest form. (Plates 20 and 40.) 

DESCRIPTION OF THE SIGSBEE WATER-CUP. 

(Plate 40.) 

In Appendix No. 55, page 192, United States Coast Survey Report for 
1854, is published a report by Assistant J. E. Hilgard concerning the action 
of sea-water on the metals used in the construction of certain instruments 
which, by the sinking of a Coast Survey schooner, had been submerged 
three weeks in five fathoms of water: Assistant Hilgard makes this remark : 
''German silver, an alloy of copjper and nickel, was not tarnished in the least 
degree, nor did it become so when afterwards exposed to the air without being 
cleaned with fresh water J' 

Probably the economy effected by using water-cups collectively would 
warrant the expense of making them wholly of German silver, although in 
the Sigsbee water-cup it is employed only for the more delicate working 
parts, the action of which might be seriously affected by corrosion, and the 
cleaning of which would be difficult. All parts not specified in the follow- 
ing description as being made of German silver are of brass. 

The cylinder A (Figs. I, II, III, IV, V). 

The thickness of metal to be no greater than is required for tlie turning of a strong screw-thread at 

The lower valve-seat B (Figs. I, II, III, IV, V), which screws to the 
cylinder by a right-hand screw-thread. 

Though the lower valve-seat may be removed, this is not necessary for cleaning; there being no sharp 
angle at its inside junction with the cylinder, a cleaning rag thrust into the cylinder from above may be made to 
reach all parts. 

The detachable upper valve-seat C (Figs. I, II, III, IV, V). 

This is made detachable that the valves may readily be removed for cleaning the parts. 

The upper poppet-valve D (Figs. I, II, III, IV, V) and the lower pop- 
pet-valve E (Fig. I), connected by a stem, the valves being adjustable by 
means of a long, fine screw turned on the connecting stem at F (Fig. I) . 

The connecting stem should be made of the same material as the cylinder and the valves, so that all may 
expand or contract in the same proportion under change of temperature. It should not be secured to the lower 
valve by passing through it, thus making a joint through the valve, but should be fastened with a screw, as 
shown faintly in Fig. I, the threads then being soldered. The stem proper of the lower valve is squared at its 
lower end for tlie reception of a clock-key or crank, that the valves may be adjusted to their respective seats. 



K O 

2: S 




> 

H 

w 
to 
o 



SPECIMENS, DENSITIES, TEMPEKATUEES, AND OUEEENTS. 93 

A small German-silver compression-spring at G (Fig. I). 

To prevent a too easy disturbance of the adjustment of tlie valves, for which purpose the sj>iiiiff should be 
under a considerable pressure when the valves are adjusted. 

The frame-work H (Figs. I, II, III, IV, V), fastened to the cylinder 
by a left-hand screw-thread, inclosing the upper valve-seat. 

A left-hand thread is employed that the action of the spring-cliimp (to ))e referred to hereafter) nuiy not 
open the joint. The parts forming the joint should be ground into place to nuxke a close contact. 

The German-silver removable sleeve I (Figs. I, III) . 

To permit the removal of the propeller-shaft from its bearings. 

The brass pin J (Figs. I, II, III, IV, V). 

The German-silver shaft K (Figs. I, II, III), with rifjM-liand screw- 
threads (forty-four to the inch) at L and M (Fig. I). 

A German-silver propeller or fly; composed of two bent blades N, N 
(Figs. I, II), the hub (Figs. 1, II, IV), the inside screw-thread P (forty- 
four to the inch) (Fig. 1), the guide-cap Q (Figs. I, 11, IV), removable, 
but fitting tight on the hub ; and the beveled lugs R, R (Figs. I, 11). 

The lighter the i)ropeller the liettt-r. as will be seen hereafter. The pitch of the propeller will also be 
referred to further on. The guide-cap and the l(j\\vr end ot the hub are made to fit close enough on the shaft to 
prevent grit or dirt from getting inside and among the screw-threads, but they should be capable of sliding verij 
freely on the shaft. The threads of the hub and shaft should work together so freely as to permit the propeller 
to be revolved by a puff from the breath. 

The German-silver bouching S (Fig. I), soldered to the frame-work. 
A German-silver screw-cap, with milled head T, T (Figs. I, II, IV), 
beveled slots U, U (Figs. I, II), and inside screw-thread V (Fig. I). 

The cap should fit the shaft in the manner described for the propeller-hub. Between the screw-cap and 
the bouching S there slioidd be a considerable clearance, xho i"t-h or more. 

A clamp composed of the two lugs W, W, the pivot-screw X, and the 
German-silver or steel sprimj-wire Y (Figs. Ill, IV, V). 



If these clamps : 




le with the tipper arm of the levi 


er a decided loop, a^ 


-, shown ou the thermoui 


cases (Plates "2 an<l 3). t 


hey ma 


y be used ou any size of soundin 


ig-rope. To change 


the power to suit diffe 


sizes of rope it is only 


ueccssa 


ry to bend the long arm of the 


lever slightly a sho 


rt distance below the pi 


screw X. It takes but i 


1 few se 


■conds to attach or remove a cup 


with these clamps. 


I have never known a 


of slipping with them. 











The cost of the water-cups is about $25 each. 

WORKING OF THE SIGSBEE WATER-GUP. 

To Aiijustthe vtiives. — Hold the uppcr valve firmly, and unseat the lower 
valve by screwing it upwards. Then, maintaining the upper valve on its 
seat with the finger — or, better, ])y turning the screw-cap down upon it — 



94: DEEP-SEA SOUNDING AND DEEDGING. 

reseat the lower valve gently. In general, it will be necessary to readjust 
the valves only after the cup has been taken apart for cleaning or for 
other purposes. 

The cup when in use comes to the surface filled with water, the screw- 
cap pressing upon the upper valve, thus securing both valves, and the pro- 
peller resting upon the screw-cap. To remove the specimen from the cup, 
first lift the propeller, and by giving it a few turns cause its threads to en- 
gage the screw-threads on the shaft ; then turn up the screw-cap until it 
uncouples. With the cup in this condition the valves may be lifted and 
the water discharged. When the screw-cap is pressing upon the upper 
valve the threads inside the former are engaged with the threads of the 
shaft, but, on screwing up the cap when its lower thread clears the upper 
thread of the corresponding series on the shaft, the cap uncouples, which 
prevents any mistake being made at this point by the person who is hand- 
ling the cup; afterwards the screw-cap may be turned in the same direc- 
tion indefinitely without jamming or changing position along the shaft. 

With the screw-cap up, and the propeller in any position, the cup is 
automatic, and may, if desired, be lowered into the water with no further 
preparation ; yet it is a good practice to first screw up the propeller by 
hand to observe if the threads are in perfect working order. 

Assuming the propeller to be low down on the shaft, or even resting 
upon the screw-cap, the action of the cup in the water is as follows : 

As it descends the valves are lifted and held up by the resistance of 
the water ; by the same agency the propeller is revolved and carried up- 
wards until, like the screw-cap, it has become uncoupled, after which it 
revolves freely on the shaft impinging against the German-silver sleeve I. 
If the propeller hub were allowed to come in contact with the sleeve while 
the screw-threads were still engaged it might remain impacted during the 
subsequent ascent. To insure uncoupling at the proper time, the guide- 
cap, which fits over the top of the hub, must be set well home in its posi- 
tion when the propeller is fitted to its shaft. It will be noticed that the 
blades of the propeller are bent along their upper edges. With the blades 
thus bent, and all parts of the propeller made very light in weight, it has 
l)een found, experimentally, that the alternating movement of translation 



SrECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 95 

imparted to tlie submerged cup by the motions of the vessel in a sea-way 
will cause the propeller, when engaged with the threads on the shaft, to 
gradually screw up rather than down. This shows that stoppages in the 
descent, whether to attach additional cups to the rope or wire, or for any 
purpose whatever, may be made with safety if the vessel be kept idle in 
the water, that is, without headway or sternboard. Were the blades not 
bent it is evident that the propeller would gradually screw down by the 
same alternating movement, since its weight would assist its action in 
screwing down but resist it in screwing up. Even thus, experiments have 
shown that with the alternating movement continued for a longer time than 
would probably be occupied at any stoppage, the propeller would screw dovrh 
onihe shaft only a small proportion of the whole distance over which it 
must pass to reach the screw-cap. It is plain that, in the event of such 
action, the propeller would rise and uncouple each time that the descent 
was continued. However, the bending of the blades insures safety, and the 
valves are left free to open during the whole descent. At any stoppage in 
the descent each cup has within its cylinder a specimen of water from its 
locality at the time being, allowing a margin of one or two feet. 

Immediately the ascent is begun the valves of each cup are pressed 
firmly on their seats by the resistance of the water, and each propeller 
■begins to screw down along its shaft under the same influence. When the 
upper thread inside the hub of the propeller clears the lower corresponding 
thread on the shaft, the propeller uncouples and drops upon the screw-cap, 
which it clutches. The screw-cap is then carried down until it comes in 
contact with the upper valve, from which position it cannot be removed by 
the action of the water or of the propeller. Both valves having thus 
become locked, stoppages may be made thereafter during the ascent with- 
out risking the identity of the inclosed specimen of water. 

The distance through which the cup must pass in order that the pro- 
peller may traverse the shaft and lock the valves may be varied by altering 
"the pitch of the propeller blades. As shown in the drawings, the propeller 
would probably not perform its whole work short of fifty fathoms. I 
settled on about twenty-five fathoms as the most convenient distance. 
With this distance it would not be prudent to require the uppermost cup to 



96 BEEP-SEA SOTJNDING AND DEEDGIHG 

bring a specimen from nearer the surface than fifty fathoms. If the pro- 
pellers were arranged to lock the valves in an ascent of about twenty-five 
fathoms and the uppermost cup were lowered only to a depth of ten 
fathoms, for instance, obviously, when that cup had arrived at the height 
of the vessel's deck, the submerged cups having passed through a distance 
of only about twelve fathoms would not have become locked. 

In Chapter II, page 40, the importance of keeping valves clear of 
muddy or gritty bottom has been stated. When a specimen of bottom 
water was desired the custom on board the ''Blake" was to fasten a cup 
about two fathoms above the sinker. A method of fastening a Miller- 
Casella thermometer case to the water-cup is shown on Plate 40. This 
method was intended to save time when the temperature and a specimen 
were to be obtained from the same depth. Since that drawing was made 
all the thermometer cases on board the "Blake" have been fitted with 
spring-clamps, rendering their attachment to the rope, independently, an 
easy and rapid operation. (Plates 2 and 3.) 

Each cup, as soon as discharged, should be thoroughly rinsed in 
fresh water. Water-cups were lowered by a rope, which for convenience' 
we styled the temperature-rope, to be described shortly. 

An explanation of some additional points connected with the cup is 
given for the benefit of those whose tastes may lead them to improve on- 
what we have done ; it being desirable that such persons should know 
the intention which induced the peculiar fashioning of the various parts. 
This, while suggesting to others, perhaps, a better mechanical shape, 
especially in details, may prevent a useless sacrifice of good features in 
the adoption of new ones. 

A cup made from the drawings and scale of Plate 40 will be of light 
weight and convenient size, holding about twenty-two cubic inches of 
water. If a little more water be needed, the cylinder, connecting valve- 
stem, and the long arm of the spring-clamp may be lengthened, no other 
changes being made. In this way the Sigsbee cups furnished the Arctic 
exploring steamer "Jeannette" were given a greater capacity than those 
made strictly by the drawings and scale of Plate 40. For the "Blake's" 
dredging cruises especially large cups were made, larger perhaps than would 



SPECIMENS, DENSITIES, TEMPEEATITRES, AND CURKENTS. 97 

now be thought necessary. These were about twelve inches between valves 
and of two and one-half inches diameter of cylinder, inside, holding about 
fifty-seven cubic inches of water, which is a little more than a quart. They 
weighed six and one-half pounds each, and were used with impunity at 
the end of the sounding-wire; but since the main object is to use the cups 
collectively, it is an obvious advantage to have them of lighter weight if 
possible. 

A very pertinent question which has often been asked is this: "Will 
the threads of the propeller-hub and shaft always engage each other as 
desired, that the two parts may couple after they have been uncoupled?" 
No failures have occurred in this respect, and, in fact, there can be none 
when the threads are in good condition, for the hub being guided at each 
extremity its movement must be true. 

The area of the upper valve proper is less than that of the lower valve, 
the set thus forming balance-valves. This arrangement resulted from a 
suggestion by Lieut. J. E. Pillsbury. It being thought doubtful by some 
persons that poppet-valves would always lift by the resistance of the water, 
Lieutenant Pillsbury suggested balance-valves for the purpose. It was at 
once evident that the use of valves so arranged would not only secure a 
favorable result in the descent, but that a desirable benefit might thereby 
be secured when the cup was ascending. When the cup enters the water, 
there being only atmospheric pressure in the chamber of the cylinder, if 
the valves do not lift there must soon prevail, as the descent continues, a 
greatly preponderating and constantly increasing pressure outside the cup, 
which must raise the connected valves. Once a current is established 
through the cup the resistance of the water acts upon the under surface of 
both valves. On the ascent both their own weight and the resistance of the 
water operate to close the valves. The valves once closed there is soon a 
preponderating pressure mside the cylinder — since the pressure outside is 
constantly lessening — and the effect of this is to seat the valves firmly. 
While it may be thought that these points are too fine to be of practical 
advantage, it is nevertheless true that there is nothing lost by having the 
mechanical arrangement of the valves theoretically correct ; while by having 
the upper valve the smaller there is gained the undoubted practical advantage 

13 D s 



98 DEEP-SEA SOUNDING AND DEEDGING. 

of exposing to the resistance of the water, in the descent, the largest possi- 
ble area of the lower valve and the projecting flange of the upper valve. 
The downward extension of the lower valve-seat is intended to concentrate 
the effect of the resisting column of water on the under surface of the 
lower valve during the descent. Lieutenant Pillsbury proposed putting 
an air-tight bulb on the connecting stem of the valves in order to render 
the specific gravity of the valves and stem thus fitted only slightly greater 
than that of sea-water. The idea is ingenious, but its adoption is hardly 
necessary. 

When a cup comes from the water the screw-cap is usually found to 
be more tightly set against the upper valve than can be attributed to the 
force which the small propeller could have exerted under the circum- 
stances. Probably the following causes operate to effect this: First, a 
slight preponderating pressure within the cup; second, the expansion of 
the metal in the change from a colder to a warmer temperature, the screw- 
cap and upper valve having come in contact when slightly contracted by 
the low temperature of deep water. 

The cup may be taken wholly apart without the aid of a screw-driver. 
In detaching the screw-cajo and the ^rojoeller from the shaft care must be taken 
not to injure the delicate screw-threads hy stripping them. 

Lieutenant S. M. Ackley proposed making a hole through the cylinder 
just below the upper valve-seat, and covering this hole securely with a thin 
piece of sheet-rubber as a permanency, the object being to prevent the 
possible escape of gases past the valves by making provision for their 
expansion within the cup. It would be interesting to experiment with 
this device. Any distension observed in the rubber disk or diaphragm on 
coming out of the water would probably recommend its adoption, although 
by its use the valves would cease to be balance-valves. 

A stop-cock device for transferring the water from the water-cup to 
another vessel without exposure to the atmosphere has received attention, 
but the design has not been completed. 

WATER densities; how observed. 
If a water specimen was to be saved for future examination its density 
was taken before bottling. Early in our work we were provided by the 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 99 

office with a special scale-areometer and its accompanying thermometer, 
which we always used thereafter. These instruments having been already 
described in Appendix No. 16, Coast Survey Report for 1874, the appendix 
is given below: 

[From the United States Coast Survey Report for 1874.] 

APPENDIX No. 16. 



practical 



DESCRIPTION OF AN OCEAN SALINOMETER, BY J. E. HILGARD, ASSISTANT UNITED 
STATES COAST SURVEY. 

The density of sea-water in different latitudes and at different depths is an element of so great 
importance in the study of ocean physics as to have caused a great deal of attention to be paid lately 
to its determination. The instruments employed for the purpose have been, almost without exception, 
areometers of various forms. The differences of density as arising from saltiness are so small that it is 
necessary to have a very sensitive instrument. As the density of ocean-water at the temperature of 60"^ 
Fahr. only varies between the limits of 1.024 and 1,029, it 
is necessary, in order to determine differences to the hun- 
dredth part, that we should be able to observe accurately 
the half of a unit in the fourth-decimal place. This gives a 
great extension to the scale and involves the use of a series 
of floats if the scale starts from fresh water, or else the 
instrument assumes dimensions which make it unfit for use 
on board ship. 

With a view to the convenient adaptat 
use, the apparatus figured below has been devised for 
Coast Survey by .\ssistaul Hilgard. 

The instrument consists of a single float about 9 
inches in length. The scale extends from 1.020 to 1.03 L, 
in order to give sufficient range for the effect of temperature. 
Each unit in the third place, or thousandths of the density 
of fresh water, is represented by a length of 0.3 of an inch, 
which is subdivided into five parts, admitting of an accurate 
reading of a unit in the fourth place of decimals by estima- 
tion. The float is accompanied by a copper can, with a 
thermometer inserted within the cavity, which is glazed in 
front. In use the can is nearly filled with water, so as to 
overflow when the float is inserted, the reading being then 
taken with ease at the top of the liquid. For convenience 
and security two such floats and the can are packed together 
in a suitable case, and a supply of floats and thermometers, 
securely packed in sawdust, is kept on hand to replace the 
broken ones. 

The following table has been derived from the observa- 
tions of the expansibility of sea-water, made by Prof J. S. 
Hubbard, U. S. N. Column II contains a table of reductions 
for temperature of salinometer readings to the standard of 
60° Fahr. To facilitate the use of this table the following 
directions are given: 

Record the actual observation of hydrometer and 
thermometer. From Column II (which is applicable to 
any degree of saltiness within the given limits) take the 
number corresponding to the observed temperature and 
multiply this number by the number of degrees and fractions of a degree that the observed temperature differs 




— Hilgard's Ocean Salinometer. 



100 



DEEP-SEA SOUNDING AND DEEDGING. 



from 60^. Apply this product as a correction, with proper sign, to the reading of the salinometer, and the result 
will be the reading of the salinometer at the standard temperature of 60° Fahr. 

Example. — ^Actual reading of thermometer = 80°. 5; actual reading of salinometer = 1.02425. 

Opposite 80°.5 in Column II is +0.0001585, which multiplied by 20.5 gives as a product +0.003249. 
Add this to the observed reading of salinometer, and 1.02750 will result as the reading of the salinometer at the 
standard temperature. 





Coeff. for re- 




Coeff. for re- 




Coeff. for re- 




Coeff. for re- 1 


Temp. 


duction to 
60°. 


Temp. 


duction to 


Temp. 


- duction to 


Temp. 


duction to 


^ 




o 




^ 




^ 




50 


-0.000108 


60 


-t-0. 000000 


70 


+0.000145 


80 


+ 0.000158 


51 


— C 




61 


-1-0. 000130 


71 


+0.000146 


81 


+0.000159 


52 


-( 


000112 


! 62 


+0.000135 


72 


+ 0.000147 


82 


+0.000160 


53 


— c 


000113 


63 


-f 0.000137 


73 


+ 0.000148 




+ 0.000162 


54 


— c 


000115 




-f 0. 000137 


74 


+0.000149 


84 


-fO. 000163 


65 


-( 


000118 


65 


+0.000138 




+0. 000151 


85 


+0. 000164 






000120 




+0.000140 




+0.000152 






57 


— c 


000120 




+0.000141 


77 


+0.000154 


87 


+0.000167 


58 


— t 


000120 


68 


-i-0. 000142 


78 


+0. 000156 


88 


+0. 000168 


59 


—0. 000120 


69 


+0. 000143 


V« 


+ 0.000157 




-1-0.000170 



A method quite different in practice for determining the density of sea-water has been suggested by Prof. 
Wolcott Gibbs, of Harvard University. It depends upon the determination of the index of refraction by means 
of an angular instrument similar to the sextant. As all navigators are familiar with the use of the sextant, and 
as the observation can be made without hinderance from the motion of the ship, this form of the instrument may 
be found to possess certain advantages. 

Note in 1876. — When the table of reductions for temperature above given was constructed, the investi- 
gations felalive to the same subject made by Thorpe and Eiicker (Eoyal Society's Proceedings, January, 1876) 
were not known. The following comparison of the results of the experiments on the thermal dilation of sea- 
water, as taken from Professor Hubbard's tables and as derived from the results of Thorpe and Riicker, show 
the differences within the range of temperature covered by our table of corrections : 



Tempera- 


Volume. 


Hubbard. 


Thorpe and 
Rucker. 


50 
55 
60 

75 
80 
85 




99895 

00000 
00067 
00142 
00221 
00309 
00402 





99902 
99946 
00000 
O0059 

00205 
00280 



An optical densimeter, invented by Professor Hilgard, was not made 
wholly available for use on board the "Blake" during the period of my 
command, but Professor Hilgard has been kind enough to prepare for this 
volume the following abstract of Appendix No. 11, Report of 1877, United 
States Coast and Geodetic Survey, in which the instrument is described. 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 101 

HILGARD'S OPTICAL DENSIMETER FOR OCEAN WATER. 

[From Coast Survey Report for 1877, Appendix No 11.] 

The determination of the density of the ocean in ditt'erent parts of the world, and at various depths, is 
admitted to be an element of the physical condition of our globe which it is important to determine with 
great precision. As the object of this notice is only to describe a new instrument for finding such densities, 
there is no occasion to discuss the importance of their ascertainment further than to consider the degree of 
precision requisite for useful results, and which can be reached by the instrumental means available on ship- 
board. Account .is taken only of the density of ocean water uninfluenced by the immediate proximity of 
fresh-water streams. As the sensible eft'ect of such is variable in different seasons and at dift'erent stages of 
the tide, no great precision in any single observation of the density of the water is useful, because the densi- 
ties will differ sensibly in adjacent threads of the current, and the value can only be obtained by the average 
of a great number of observations of approximate accuracy. Ordinary hydrometer-floats ranging from the 
density of fresh water to that of ocean water, with a stem of three inches graduated from 1.000 to 1.030, will 
sufficiently serve such experimental purposes. When, however, we get away from such local conditions, and 
inquire into the general regimen of the ocean, affected in part by the fresh-water outflow from the continents, 
but mainly by the general thermal circulation, it becomes iniporiant to measure the differences of density with 
the gi'eatest precision that can practically be obtained. 

These considerations are equally impoitant with regard to the density of ocean water in different parts 
of the surface and at various depths. If the specimens secured could be preserved without sensible change 
until they could be opportunely submitted to a laboratory investigation, the task of the naval officer would be 
reduced to collecting specimens and hermetically sealing them up, but it is reasonably to be supposed that he 
would have a desire to ascertain the results for himself 

The want of suitable instruments has been met to a certain degree by hydrometers (which might prop- 
erly be called " stem floats") specially adapted to sea-water. This method of ascertaining the density does not, 
however, admit of great precision on shipboard, because the float partakes of the movements of the vessel, 
and oscillates between wide limits — wider in proportion to its sensitiveness, and generally nncomformable to 
the oscillations of the ship. Hence it becomes very difficult to read the average position of the float with a suf- 
ficient degree of precision, unless the sea be exceptionally calm. 

The average density of the ocean properly speaking, unaffected by local causes, will not vary, when 
reduced to a common temperature, more than one-thousandth part from the average value. It is therefore nec- 
essary, in order to obtain any useful results, that the density should be ascertained to at least one-ten-thou- 
sandth part of the whole, or practically a unit in the fourth decimal place. Now. a hydrometer or stem-float of 
that degree of sensibilitj', while perfectly available on shore, is so susceptible of the movements of the vessel 
as generally to render observations quite impracticable on shipboard. For this reason it has been deemed 
advisable to abandon that most direct mode of ascertaining the density, and to resort to other means offered us 
by physical science. 

With this view, the optical densimeter, described below, has been devised, which obviates all the diifl- 
culties arising from the movement of the vessel. The basis of this instrument is the change in the refractive 
power of a saline solution of greater or less density. The instrument consists, substantially, of a hollow prism 
filled with the water under observation, transmitting from a collimating telescope a line of monochromatic light 
to an observing telescope in which the refracted position of that line is read by means of a micrometer. The 
monochromatic light employed is a sodium flame, obtained by adding a small proportion of a solution of com- 
mon salt to the alcohol of the lamp. The accompanying illustration exhibits the instrument in the proportions 
that have been found advantageous. The temperature of the liquid under observation is found by means of 
a thermometer inserted through the neck of the hollow prism, but which is withdrawn when the optical obser- 
vation is made. 

The glass prism rests on three little knobs, so as to have a firm support. Attached to the stand carry- 
ing the telescopes are two guides, by means of which the prism is made always to occupy exactly the same 
position, so that all observations are made under the same angle. A small thumb-screw on the side of the prism, 
not seen in the plate, forces the prism closely into the guides. 



102 DEEP-SEA SOUNDING AND DEEDGING. 

It is obvious that the sensibility of this apparatus is not affected by the movements of the vessel, and 
that its power of measurement might be increased by either enlarging or increasing the power of the telescopes, 
or by introducing an additional prism. But it will be seen at once that the practical accuracy is limited to the 
ascertainment of the temperature at which the observation is made. 




Optical Densimeter. 



Now, at the average temperature at which such observations would be made — say 68° F. or 20° C. — a 
change of one degree Fahrenheit causes a change of specific gravity of about 0.0002, and since we cannot 
expect to ascertain the temperature more correctly than within two or three tenths of a degree Fahrenheit, it 
is obvious that any attempt to ascertain the density more nearly than 0.00006 would prove futile on that 
account. 

The observations made with the optical densimeter show that a single determination by this instrument 
possesses that degree of accuracy, and any greater degree of refinement would be lost in the uncertainty of the 
physical conditions of the specimen. 

The reading of distilled water being a fixed point on the scale of reference, it is not necessary to observe 
distilled water for every determination. A frequent check should, however, be made of the constancy of this 
reading. 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 103 

The following will serve as an example of record and reduction of observations: 



No. of 
sample. 


Latitude 
and lon- 
gitude. 


Depth in 
fathoms. 


Date of 
taking. 


Date of 
tion. 


Microme- 
ter read- 
ings. 


Temp., 
Fahr*.' 


Reduced 
micrometer 
reading. 


Difference 
ofmicro- 


Specific 
gravity 
at60°F. 


Distilled 








June 28 
June 28 


274.8 
75.4 
75.1 
76.1 

275.2 


70O 
71° 
70° 


302.5 
690.5 
690.6 




water. 

28 

29 






June 22 
June 22 




1.00000 
1.02769 




275.3 

655.0 
54.6 
54.3 

54.8 


t 72i W. 


1 100 

} " 


388.0 


654.5 

58.2 
57.3 
658.1 


658.3 


388.1 1.02770 









104 



DEEP-SEA SOUNDING AND DEEDGING. 



SERIAL WATER TEMPERATURES; HOW TAKEN. 

As has been shown in Chapter I, obtaining serial WEPter temperatures 
was a very important feature of our work. The instrument used by us was 
the Miller-Casella deep-sea maximum and minimum thermometer. The 
readings were first recorded in a book containing forms like that shown 
below, and were afterwards transferred to the General Record. Form 3, 

given in Chapter VI. 

FOEM 2. 
U. S. COAST SURVEY STEAMER "BLAKE " 

Locality, . Date, , 18 — . Sounding No. — . Line, — . 





TBMPERATUBES. 




Depth, 


Beading. 


Correction. 


Corrected. 


No. of the 
Thermometer. 


Kind of 

Thermometer 

used. 


REMARKS. 




Min. 


Max. 


Min. 


Max. 


Min. 


Max. 




Surface. 


















Temperature of Air 

Temperature of Thermometer- 
locker. -. 



All bottom temperatures were taken by attaching a thermometer to the 
stray-line of the sounding-wire, or to the sounding-rope just above the 
sinker. Those at intermediate depths were obtained, for the first three years, 
with the aid of a hemp rope of one and one-half inches or one and three- 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 105 

fourths inches circumference, called the temperature-rope. This rope, 
when we were at work, was kept laid down upon the quarter-deck in long- 
coils or fakes, with the greatest diameter athwartships, each fake only 
partially covering the preceding one; in which way the fakes were gradu- 
ally worked along the deck for a considerable distance, forming a worm. 
This method we adopted from Commander Howell's practice, and it was 
found to work admirably, one man being able to manage the coil handily 
at a very rapid rate of reeling in. The chief advantage derived was the 
free circulation of air about the various parts. Our upper-deck being 
painted, we had no trouble in keeping the rope in good condition for a 
long time. The size of the rope was larger than necessary for the purpose 
of taking temperatures, but we also used it for sounding in depths less than 
one hundred fathoms; made it serve as an anchoring-line for a boat when 
taking current observations, and have even anchored the vessel by it, with a 
kedge, for short times. One-inch hemp rope would suffice for taking temper- 
ature observations and for obtaining water specimens. The temperature- 
rope, weighted with a fifty-pound lead sinker, was payed out through a 
snatch-block hooked to a swivel-eye in the end of an iron crane, the crane 
being shipped into a socket on the vessel's rail; over the bowsprit. (Plate 
24.) Thermometers and water-cups were attached to the rope at intervals 
as desired. The descent of the rope at any stage could easily be checked 
and stopped by two or three men. The system of marking this rope was 
very simple. It is given from memory. 

To one hundred fathoms the marks were the same as are in general 
use for lead-lines; after that, as follows: 

At 100 fathoms, 1 white rag. 

At 200 fathoms, 2 white rags. 

At 300 fathoms, 3 white rags. 

At 400 fathoms, 1 red rag. 

At 500 fathoms, 2 red rags. 

At 600 fathoms, 3 red rags. 

At 700 fathoms, 1 blue rag. 

At 800 fathoms, 2 blue rags. 

At 900 fathoms, 3 blue rags. 

14 D S 



106 DEEP-SEA SOUNDING AND DEEDGING. 

At 1,000 fathoms, 4 white rags. 

Intermediate fatlioms were marked by using pieces of soft leather 
punched through with a large hole one-half inch in diameter, or small 
holes one-quarter inch in diameter, or both; thus — 

At 10 fathoms, 1 small hole. 

At 20 fathoms, 2 small holes. 

At 30 fathoms, 3 small holes. 

At 40 fathoms, 4 small holes. 

At 50 fathoms, small hole, 1 large hole. 

At 60 fathoms, 1 small hole, 1 large hole. 

At 70 fathoms, 2 small holes, 1 large hole. 

At 80 fathoms, 3 small holes, 1 large hole. 

At 90 fathoms, 4 small holes, 1 large hole. 

The marks throughout the length of each succeeding 1,000 fathoms 
were a repetition of those of the first 1,000 fathoms, excepting that the 
service or navigational marks, as on the outer one hundred fathoms, were 
not repeated, the leather tallies being used instead. 

If marks were needed only at every twenty-five fathoms, the fifty, one 
hundred, and 1,000-fathom marks might be retained as given, and a knotted 
piece of cod-line, or other small stuff, used for the twenty-five and seventy- 
five-fathom marks. 

The leather tallies are very distinct at night, holes being more readily 
distinguishable than color by the light of a lantern, but the trouble with 
them — and with all other pendent marks in long-continued use — is their 
liability to be frayed or torn off in passing through blocks or over winch- 
heads; it would, therefore, be a convenience to dispense with marks and 
pay out over a measuring pulley. 

For taking serial temperatures in the season of l877-'78, we fitted out 
with 1,000 fathoms of one-eighth inch diameter steel-wire rope, having a 
hemp heart. This was wound upon an iron drum or reel controlled by a 
friction-brake. (F, Figs. 1 and 2, Plate 29.) On the axle of the reel was 
a V-groove pulley for connecting by a rope belt with the main hoisting- 
engine, for reeling in. It will be shown hereafter how, during this season, 
we reeled in our heavy wire dredge-rope by taking it around a winch-head 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 107 

of the engine "ow the bight,'' whence it was passed to the reel. This was 
inadmissible with the smaller rope, owing to its greater tendency to kink 
when released from tension; consequently it had to be taken directly 
upon the reel after passing in over the leading-block at the end of the 
crane. With the wire rope we could work with great rapidity, but its 
vibration in the water was so decided that it sometimes had the effect of 
displacing the indices in the tubes of the Miller-Casella thermometers; 
hence we were not sorry when the rope parted while we were taking serial 
temperatures in a heavy sea. It was supposed to have a breaking strain 
of 1,900 pounds, but it parted when only five hundred fathoms had been 
payed off the reel, although a short time before we had taken a cast and 
bottom temperature in over 1,500 fathoms, without the least trouble, by 
means of the piano-forte wire. 

Doubtless the marks worked through between the strands may have 
weakened the steel temperature-rope somewhat in places, but it is probable 
that steel rope of such small size — needing to be made of very small wires 
to secure flexibility — cannot be depended on to withstand the violence of 
deep-sea work for any great length of time, as the strength of the wires 
will soon become impaired by corrosion. I think steel rope of one-fourth 
inch diameter, with a hemp heart, would serve for a temperature-rope, 
particularly if used in connection with an accumulator having enough 
elastic movement to afford a slight cushioning. 

After parting our steel temperature-rope, serial temperatures were taken 
with the aid of piano-forte wire during the remainder of the season, a spare 
sounding-reel being used for the purpose and no accidents happening. 

During our first season, when working in very deep water, we usually 
took the sounding and the temperatures at the same time, sounding from 
the bow and lowering the thermometers from the gangway. This we did 
without trouble; but in the next season, south, we twice fouled the wire 
with the rope in strong currents, after which we did not attempt serial 
temperatures until the sounding had been completed. 

Commander Bartlett has used the steel dredge-rope for taking serial 
temperatures. 

The instrument next to the Miller-Casella most generally used for 



108 DEEP-SEA SOUNDING AND DEEDGING. 

finding sub-surface temperatures is a recent form of Negretti and Zambra's 
deep-sea thermometer. 

DESCRIPTION OF THE MILLER-CASELLA DEEP-SEA THERMOMETER. 

(Plates 21, 22.) 
A glass tube bent in the form of U is fastened to a vulcanite frame, 
and to the latter are screwed white glass slabs containing the graduated 
scales. Each limb of the tube terminates in a bulb. ' A column of mercury 
occupies the bend and a part of the capillary tube of each limb. The 
large bulb and its corresponding limb, above the mercury, are wholly 
filled with a mixture of creosote and water; the opposite limb above the 
mercury is partially filled with the same mixture, the remaining space 
therein being occupied by compressed air. In the mixture on each side is 
a steel index having a horse-hair tied around it near the upper extremity. 
The ends of the elastic horse-hair being held in a pendent position by the 
inner walls of the tube exert enough pressure to oppose a frictional resist- 
ance to a movement of the index in elevation or depression. As thus 
described, the instrument is a self-registering maximum and minimum 
thermometer for ordinary use. The indications are given by the expan- 
sion and contraction of the creosote and water mixture in the large, full 
bulb. The instrument is set by bringing the lower ends of the indices 
in contact with the mercury by means of a magnet provided for the 
purpose. Then, when the instrument is submitted to a higher tempera- 
ture, the expansion of the mixture in the large bulb depresses the column 
of mercury on that side and correspondingly elevates it on the other side. 
A decrease of temperature contracts the mixture in the large bulb, and by 
the elastic force of the compressed air in the smaller bulb a transference of 
the column of mercury takes place in precisely the reverse manner to that 
which occurs on a rising temperature. Thus the mercury rises in the left 
limb for a lower and in the right limb for a higher temperature. The 
greater the change of temperature the higher the point reached in the 
respective limbs ; hence the scale on the left is graduated from the top 
downwards, and that on the right from the bottom upwards. The rising of 
the mercury in either limb carries with it the index of that limb, and on 






g ?3 -p ." 

OS.in 
S25 




r 

> 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 109 

the retreat of the mercury the index remains at the highest point reached. 
The bottom of the index, being the part which has been in contact with 
the mercury, gives the point at which to take the reading. 

It was found that instruments made as described were liable to con- 
siderable error, in excess, amounting sometimes to as much as ten degrees 
in deep casts, due to the pressure of the water ; the pressure, by compress- 
ing the large, full bulb, forced part of the contents into the capillary tube, 
producing the same result as an increase of temperature.* 

In April, 1869, Dr. D. A. Miller, vice-president of the Royal Society, 
proposed surrounding the larger bulb by another bulb, the latter to provide 
a shield for the former. All thermometers styled Miller-Casella are con- 
structed with this outer bulb, which is fused to the stem or capillary tube 
just below the inner bulb. The space intervening between the two bulbs 
is nearly filled with alcohol, a small portion or bell containing only rari- 
fied air and the vapor of alcohol. The space filled by the air and vapor 
receives any of the spirits that may be displaced by the compression of the 
outer bulb. Thus the inner bulb is almost wholly relieved from pressure, 
and the alcohol serves as a medium for the transmission of temperature. 
Dr. C. Wyville Thomson, now Sir C. Wyville Thomson, estimated from 
the results of experiments with a number of the protected instruments 
that their mean error due to pressure was as follows : 

For 250 fathoms, 0°.079 C. ( = 0°.142 F.). 
For 2,500 fathoms, 0°.79 C. (= 1°.42 F.). 

These, if applied as corrections, are subtractive. 

Of thirty-six Miller-Casella thermometers recently purchased by the 
Coast and Geodetic Survey, the mean error of all due to a pressure of 
three and one-half tons was l°.l Fahrenheit, as ascertained by the makers. 
The greatest single error was 1°.7 and the least 0°.6. 

The instrument attached to its frame is kept, both for stowage and 
use, in a perforated copper case. As provided by the manufacturers the 
case must be attached to the rope by stops, but all of the "Blake's" cases 
are fitted with the spring-clamp shown on Plates 2 and 3. 

*For an interesting and instructive d^escription of the Miller-Casella thermometer, see "Depths of the 
Sea," by Dr. C. WyvUle Thomson, pp. 288-299. 



110 DEEP-SEA SOUNDING AND DEEDGING. 

The Miller-Casella thermometer is made by L. Gasella, scientific 
instrument maker, 147 Holborn Bars, London, E. G. The catalogue 
price of the instrument is £2 5s,, with case and magnet. 

REMARKS CONCERNING THE MILLER-CASELLA THERMOMETER. 

There can be but little doubt that the Miller-Casella thermometer? 
when properly managed, gives in most cases a close approximation to the 
temperature of the depth to which it has been lowered, but the immobility 
of the indices, after the retreat of the mercury, being dependent on friction 
alone, is not absolutely assured, and herein, perhaps, lies the chief objec- 
tion to the iiibtrument. There is nothing in its appearance to point out 
an error in this respect when it has occurred. The only safeguard, when 
but a single instrument is used for each depth of a series, is to compare 
carefully the indications at the same or different series of observations, 
the surest means of doing this effectually being to construct curves like 
those shown on Form 14 (Chapter VI). 

When all the indications of a set of serial observations are correct 
the gradients of the curve sometimes change rapidly, but a decided angu- 
lar deviation from the general contour of the curve is perhaps nearly always 
due to an erroneous record by the instrument. 

Sometimes a particle of mercury gets above an index, or one of the 
latter becomes immersed in the mercury; an index becomes jammed in the 
tube, or the column of mercury breaks. These are mere accidental defects, 
which, being apparent to the eye, point directly to an error, and they may 
in most cases be remedied on board the vessel. 

When a particle of mercury gets above an index the latter may be 
drawn by the magnet into an enlargement or swelling of the tube, which 
all of these thermometers have just below each bulb ; the mercury will 
then fall clear. When a column of mercury breaks, its integrity may be 
restored by placing the instrument in warm water or by gently tapping 
the bottom of the frame against some resisting substance, both of which 
methods require caution. On one occasion, in my experience, when the 
water was too warm there was a general disturbance inside the tube, which 
ruined the instrument ; it was, perhaps, caused by part of the compressed 



§" S H ^ ^ 

S S >ci >T3 ^' 

I. 2^^ 

-■ Sow 



ffi r S 




> 



SPECIMENS, DENSITIES, TEMPEEATTJEES, AND CUEEENTS. Ill 

air being carried by expansion into the opposite limb. The tube is almost 
certain to become loosened on the frame by the tapping process, which 
reminds me of a detail in the construction of the instrument that brings 
about much annoyance. The fastening which is intended to hold the tube 
in place on the frame is a soft copper band passing half around the tube 
at the bottom of the bend and fastened only by one end to the frame. The 
object of this is probably to allow for the expansion of the glass, and to 
give a slight cushioning — enough to prevent the tube from breaking in 
the event of a violent shock such as would be caused by the case striking 
on hard bottom, but in prolonged work — or in tapping the frame — it per- 
mits the shifting of the scale, sometimes as much as li°. 

For several years after construction thermometers undergo a change 
which results in a displacement or ''elevation ' of the zero point, sometimes 
amounting to as much as 2°, making the indications too low. There is a 
scratch on the tube of the Miller-Gasella thermometer at or near the freez- 
ing point, and others at intervals of 20°. These are probably made in the 
process of calibrating the tube. Should the scale shift, the scratch nearest 
the freezing point, or any other, may be made use of to effect a readjust- 
ment, if the point on the scale to which it corresponds has been previously 
ascertained. 

On board the "Blake" all attempts to extricate an index which had 
become immersed in mercury were unsuccessful. An index jammed in 
the tube may sometimes be cleared by alternately tapping the frame and 
using the magnet. If it can be drawn up into the enlargement of the tube 
already mentioned it may be found in working order when again drawn 
down. Tapping the frame or swinging it about the head for the same 
purpose should not be allowed except as a last resort, and then only in 
the presence of the person charged with the care of the instruments, who 
should verify the correctness of the scales afterwards, 

A great advantage afforded by the Miller-Casella thermometer is its 
adaptability to collective use; that is, it may be used to obtain tempera- 
tures at various depths at a single haul, by employing it in any number 
desired, one or more at the several depths of a series. Although the instru- 
ment sometimes records erroneously through the disturbance of the index, 



112 DEEP-SEA SOUNDING AND DEEDGING. 

several of them lowered to the same depth would, by checking each other, 
make the probability of error in this respect very remote. 

Under certain relative thermal conditions of air and water a maxi- 
mum and minimum thermometer may not give trustworthy indications 
when set as usual — that is, at air temperature. We will consider an 
actual case from the "Blake's" work: 

Air 51 

Water : 

Surface 71 

50 fathoms 63 

100 fathoms 60^ 

200 fathoms 50 



The indices of all the instruments are set at 51°, the temperature of 
the air. The instruments at fifty and one hundred fathoms will not indi- 
cate the temperature of their respective depths by the minimum scale, 
because the mercury in the minimum limb will retreat from the index in 
water which is of a higher temperature than that at which the instruments 
were set. The maximum scale may give true indications at those depths 
if in the passage of the instruments through the warmer upper strata the 
indices are not carried above 63° and 60i° respectively. This is merely a 
case at hand, but it shows that other cases might arise in which much 
would be left to conjecture. 

The way in which we managed to make the Miller-Casellas serve our 
purpose in this and similar instances was to immerse them in warm water, 
raising their temperature considerably above that of the air; then, after 
setting them while in the warm water, to attach each in turn quickly to 
the rope and lower it at once into the sea. The minimum scales then 
gave acceptable readings. The case already presented is a representative 
one of a class, and a general rule may be stated as follows : The tempera- 
ture of a stratum which is at once colder than the strata above and warmer 
than the air will not be indicated at all by the minimum scale, and often 
only with uncertainty by the maximum scale. 

From what has been said it is seen that a maximum and minimum 
thermometer is not well adapted to ascertaining the temperature of inter- 
mediate warm or cold strata. 



SPECIMENS, DENSITIES, TEMPERATUEES, AND CURRENTS. 113 

An important matter to know when using any thermometer in deep-sea 
operations is the time that it requires to take up any change of tempera- 
ture. The Miller-Casella thermometer, being protected by the outer bulb, 
is sluggish in its action, particularly as its indication nears the temperature 
of the surrounding medium. Commander Lester A. Beardslee, U. S. N., 
made a series of experiments with the Miller-Casellas while on duty with 
the Commission of Fish and Fisheries. Through the courtesy of Prof. 
Spencer F. Baird, Commissioner, I am enabled to give one of Commander 
Beardslee's tables. 

In each case the Miller-Casella and a standard were simultaneously 
placed in a bath, the temperature of which was lower than the temperature 
indicated by the instrument at the instant of immersion. Commander 
Beardslee thus describes the standard thermometer used for comparison : 

" A mercurial standard, made by L. Casella, of London, No. 7432, reading from zero up to 120°, on a 
scale marked on the glass, and twelve inches long, giving 10° to the inch; bulb cylindrical, .75 of an inch in 
length. No mounting." 

Concerning the ice-bath tests, the last two of the series, he says : 

"In test No. 1, in ice, the instrument (Miller-Casella) was placed on its back in a trench out in the ice, 
and the bulbs covered with pounded ice. The mercury corresponded in its action very closely to the action of a 
bath of 50*^ until it reached that point. 

" In test No. 2 the upper portion of the ebonite guard was removed, thus letting the crushed ice come into 
immediate contact with the upper portion of the bulbs. This induced quicker action, but still slower than a bath 
of 35°, and at last, as in former cases, the mercury apparently ceased to fall at 35°." 

These and other experiments with the Miller-Casellas, by Commander 
Beardslee, are given in Appendix C, Report of the Commissioner of Fish 
and Fisheries for 1877, Prof. Spencer F. Baird, Commissioner. 

15 D s 



114 



DEEP-SEA SOTJNDING AND DEEDGmG. 





















Experiments with Miller-Casella No 


1844. 






















Bath, 60°. 


Bath, 55°. 


Bath, 50°. 


Bath, 45°. 


Bath, 40°. Bath, 35°. 


Ice-bath, 32i°. Ice-bath, 32*°. 


•3 
1 


1 
1 


1 


1 


i 


1 
1 


1 
g 


t 
1 


1 
1 


1 


1 


1 


1 

1 


1 


1 

a 


■s 

1 




o' 06 
20 

40 

1 00 
1 20 

1 40 

2 (JO 

2 40 

3 00 

5 00 

6 00 

8 .00 

9 00 

H 00 


7C 

60 
60 

GC 

6C 
60 












5 
5 

5 
5 


68 
67 

66 
65 

64 
"^ 
62 
61 

61 
61 

61 


2 
5 








8 

2 



70 

55 
55 

55 
55 
65 
55 
55 
55 
55 

55 
55 













70 

64 
62 

59 
58 

57 
56 

55 
55 

55 
55 
55 




5 
5 

2 
2 


6 

2 


7C 

50 
5C 

50 
50 

50 
50 

50 
50 

50 
50 

50 



2 

2 

5 

5 

2 


2 

4 


7( 

65 
63 

59 
58 

56 

55 

52 
52 

51 
51 

51 





5 

6 


6 

2 

2 
2 




70.0 

45^0 
45.0 

45^0 
45.0 

id'.d 
45.0 

45! 

45.0 

45! 

44.8 

45! 

45.0 
4.5.0 


70.0 
67.5 

56] 

54! 

53.0 

is'.s 

47.5 

46! 
46.0 

45.' 8 
45.8 


7C 

40 
40 

40 
40 

40 
40 

4C 
39 

4C 





2 
2 
2 
2 



1 

2 
2 



7C 

59 
56 

54 
52 

4E 

44 
42 
41 
41 

40 
40 




5 

4 

1 


2 

2 
6 


70.0 

3416 
34.6 

3416 
34.6 

35! 

35.0 
35.0 
34.6 
34.6 
34.8 
34.5 
34.5 
34.5 
34.5 


70 
58 

48 

44 
43 
42 

37 

35 
35 

34 
34 




5 




5 
5 

5 





'5 
5 


70 
38 
32 
32 

32 
32 
32 
32 
32 

32 
32 
32 
32 
32 
32 
32 

32 


5 
5 

5 

5 
5 

5 
5 

5 
5 

5 
5 

5 


67 
63 

58 
57 
56 
54 
52 
50 
49 

45 
43 

40 
39 

35 


5 


8 
2 


5 




5 
5 


70.0 
32.5 
32.5 
32.5 
32.5 
32.5 
32.5 

3215 
32.5 

32.5 
32.5 
32.5 
32.5 
32.5 

32-5 

32! 5 

32. ,5 


70 
66 

57 
54 

5C 

48 

46 

4C 

37 
37 
36 

3« 

35 
35 

35 
35 





12 00 






































14 00 
























15 00 
























































22. 00 






















. .. - 




6 1 32.5 




25 00 

















































































































It should be remembered that a tliermometer in actual use at sea is 
recording during the descent, which may be taken into account in time 
allowance. It will also register changes more quickly when passing 
through water than when resting in a still bath. 

DESCmPTION OF NEGRETTI & ZAMBRA's DEEP-SEA THERMOMETER. 

(Plates 21, 22, and 23.) 

The following description of this thermometer is copied from the cata- 
logue of the makers, Messrs. Negretti & Zambra, Holborn Viaduct, Lon- 
don, E. C. This is done for convenience, not necessarily as an expression 
of my opinion. The few words interpolated by me are inclosed in brackets. 

The letters of reference employed in the catalogue, being only three in 
number, are retained, although the plates given in this book are not lettered. 

Negretti & Zambra's thermometer in a very different shape was sent 
us for trial, on board the " Blake," during the early part of my command, 
but it was so cumbersome, expensive, and left so much open to doubt in its 
indications, that it was reported on adversely to the Superintendent of the 
Coast and Geodetic Survey. Since then the makers have issued it in a 



SPECIMENS, DENSITIES, TEMPEEATURES, AND CURRENTS. 115 

shape that seems to promise much in the way of correct results. It is still 
open to some improvement, even for taking a single temperature at a haul, 
and it cannot be used collectively like the Miller-Casella, although it is 
probably more trustworthy when used singly. This late form of the instru- 
ment has been used in the Caribbean Sea and Passages by the "Blake" 
under the command of Commander Bartlett, and also in the Arctic Sea 
by the Norwegians. 

"The construction of this thermometer will be readily understood by reference to [Plates 21 and 22]. 
The bulb is cylindrical, and mercury is the thermometrical fluid. The neck of the bulb is contracted in a 
peculiar manner at A [immediately below the bulb], and upon the shape and flneness of this contraction 
the success of the instrument mainly depends. Beyond A the tube is bent, and a small catch reservoir is 
formed at B [in the bend], for a purpose to be presently- explained. At the end of the tube a small receptacle, 
C, is provided. When the bulb is downward the glass contains sufficient mercury to fill the bulb, tube, and 
a part of the receptacle C. if the temperature is higlu leaving sufficient space in C. ^Vhen the thermometer 
is held bulb upward the mercury breaks at A, but by its own weight flows down the tube, filling C and a 
portion of the tube above C in relation to the existing temperature. The scale accordingly is made to read 
upwards from C. To set the iustruuieut for observation it is only necessary to place it bulb downward, then 
the mercury takes the temperature just as au ordinary thermometer. When at any time or at any place the 
temiierature is reijuired. all that has to be done is to turn the thermometer bulb upward and keep it in this 
position until read oft'. The reading may be taken at any time after, for the quantity of mercury in the lower 
part of the stem which gives the reading is too small to be sensibly influenced by a change of temperature, 
unless it is very great, while that in the bulb will continue to contract with greater cold and to expand with 
greater heat, and in the latter case some mei-cury will pass the contraction A and may fall down and lodge 
at B [in the catch reservoir], but it cauuot go further so long as the bulb is upward, and thus the temperature 
to be read ott' will not be vitiated. Now, whenever the thermometer can be handled it can readily be turned 
bulb upward for reading off the existing temperature. It must be clearly understood that the thermometer 
is only intended to give the temperature at the time and place when and where it is turned over; it is simply 
a recording thermometer ; it cannot be used as a self-registering maximum or minimum, though it could be 
constructed to act as a maximum if required. But at a depth in the sea some contrivances must be provided for 
turning the thermometer bulb upward. For this purpose the thermometer is fitted into a wooden frame, loaded 
with shot, free to move from end to end of it, and heavy enough to render the whole instrument just buoyant in 

"In using the thermometer a cord is rove through the hole in the frame nearest the bidb, and the 
instrument is fastened by this cord to the sounding-line. In descending the thermometer will be pulled down 
with the bulb downwards [Fig. 1, Plate 23], but upon being pulled up the instrument, owing to the 
resistance through the water, and consequent displacement of its center of gi-avity, will turn over and 
come up bulb uppermost [Fig. 2, Plate 23] ; the temperature of the spot where it turned over will then 
be indicated. 

"As regards the thermometer itself, it was necessary, in order to make it perfectly satisfactory, to 
protect it against pressure, even if intended for shallow seas as well as for the deepest. For whether used 
in deep or shallow water, unless withdrawn from pressure, its indications would always be more or less 
in error. Like an ordinary thermometei-, it is devoid of air, and so quite different from Sixe's, which, 
containing compressed air, has a certain internal resistance. Hence it would be more affected by pressure 
than Sixe's, however thick the glass of the bulb. By the simple expedient of placing the thermometer 
entirely in a shield of glass hermetically sealed the effect of external pressure is entirely eliminated. 
The shield must, of course, be strong. It need not be exhausted of air. It must, however, render the 
enclosed thermometer more difficult to be affected by changes of temperature ; in other words, it will make 
it sluggish. 

"To counteract this sluggishness in that portion of the shield surrounding the bulb some mercury is 
introduced and confined there by a partition cemented in the shield around the neck of the thermometer 



116 DEEP-SEA SOUNDING AND DEEDGING. 

bulb. This mercury acts as a carrier of heat from the exterior of the shield to the interior of the thermometer ; 
and the efficacy of this arrangement has been experimentally determined, the instrument thus protected being, in 
fact, far superior in sensibility to Sixe's thermometer. 

"So long as the shield withstands the pressure — that is, does not break — the thermometer will be 
unaffected by pressure, and there is abundant experience to show that siich a shield will stand the pressure 
of the deepest ocean. The greatest pressure can never afiect a thermometer so protected. Doubtless the 
shield will be compressed a little under great pressure, but this can never exert an internal pressure suffi- 
cient to have an appreciable effect upon the thei-mometer. This method of shielding is quite efficacious, 
and deep-sea thermometers so protected do not require to be tested for pressure in the hydraulic press. 
The thermometer will simply require to be tested for sensitiveness and for errors of graduation very accu- 
rately, because it is a standard instrument adapted to determine very small differences of temperature as 
well as large ones, even one or two tenths of a degree in shallow waters. The test for sensitiveness should 
determine how many seconds the instrument requires to take up a change of five degrees rise or fall, and 
the time has been found from five to ten seconds. 

"A considerable number of these instruments have already been tested at the Kew Observatory with 
perfectly satisfactory results, which place beyond doubt their value as standard deep-sea thermometers. 

"Thus, provided the turning-over gear is found to answer, this instrument evidently possesses great 
advantages. It has no attached scale, the figuring and graduations being distinctly marked on the stem 
itself, and the shield eftectually preserves them from obliteration by sea-water. The part of the stem which 
forms the background to the graduations is enameled white to give distinctness to the mercury. 

"The hole at the top of the frame is for the purpose of lowering and keeping the thermometer upright 
until it has reached the water. This is effected by putting a cord through the hole and both ends of it kept in 
the hand until the thermometer has reached the water, then one end is let go and the cord pulled on board. 
This operation is not imperative', but it saves the thermometer from being knocked about previous to reaching 
the water. 

"Price for Negretti & Zambra's new patent standard deep-sea thermometers, £2 10s." 

REMARKS CONCERNING NEGRETTI & ZAMBRA's THERMOMETER. 

Previous to their use on board the "Blake" Prof. Spencer F. Baird 
had used them in the work of the Commission of Fish and Fisheries as 
deep as two hundred fathoms, and thought highly of them. 

Commander Bartlett, while thinking well of them, found that their 
wooden cases when recovered from eight hundred fathoms were com- 
pressed and shriveled. The pressure at eight hundred fathoms is about 
one ton on a square inch. Prof. J. E. Hilgard suggests that the wooden 
case might be replaced by a case of thin metal, filled with paraffine. 

The Superintendent of the Coast and Geodetic Survey wishing to 
make a preliminary trial of them in actual use in advance of reports from 
Commander Bartlett, a few experiments were carried out by Lieut. S. M. 
Ackley, commanding the Coast Survey schooner "Eagre." The following 
describes some of these experiments: 

Experiment No. 1. — Lower the mercury to freezing point (32°), then reverse, bringing the bulb 
uppeiTOOSt. While retained in that position submit the instrument to a temperature of about 85°. Note if 
the catch reservoir wholly or partially fill, and if it overflow at what temperature as indicated by the 
instrument. 

Jieport. — "The catch reservoir partially filled but did not overflow." 



U. S COAST SURVEY. 



DEEP- SEA SOUNDING AND DREDGING. 



DESCENDING-. 



ASCENDING. 





THE NECRETTI-ZAMBRA DEEP-SEA THERMOMETE"R IN USE. 



SPECIMENS, DENSITIES, TEMPEEATUEES, AND CUEEENTS. 117 

An instrument in the ascent from deep water will pass through water 
of a higher temperature than that in which it reversed; hence the catch 
reservoir will contain some mercury on arriving at the surface. In experi- 
ment No. 1 a temperature higher than 85° might have been chosen, but 
other experiments have shown that the catch reservoir will not be made 
to overflow by any higher temperature to which the thermometer would 
be exposed in work at sea. 

Experiment No. 2. — With the catch i-eservoir partially filled, as in experiment No. 1, tilt the thermometer 
case and slap it roughly. Note if any of the contents of the reservoir pass down into the tube; also if the bulb 
discharge any more mercury into the reservoir under this treatment. 

Report. — "None of the contents of the reservoir passed down into the tube. Bulb did not discharge more 
mercury into the tube." 

Experiment No. 3. — Lower three Negretti & Zambra thermometers, attached as nearly as may be to the 
same place on the rope, to a depth of 500 fathoms, and haul back without stopping at that depth or at any point 
on the ascent. Note the indications given by each instrument. 

Beport. — "Instrument No. 4, 47°. 5; instrument No. 5, 47°. 5; in.strument No. 6, 47°. 5." 

Experiment No. 4. — The same as experiment No. 3, excepting to delay seven minutes at the depth of 500 
fathoms before hauling back. 

•JJepor*.— "Instrument No. 4, 46°.2; instrument No. 5, 46°.2; instrument No. 6, 46°.2." 

Experiment No. 5. — The same as experiment No. 3, excepting to delay seven minutes at 500 fathoms, and 
again seven minutes at 300 fathoms on the ascent. 

Sepoi-t.—" Instrument No. 4, 47°; instrument No. 5, 60°; instrument No. 6, 47° — vessel drifted quite fast, 
so that the line was at an angle." 

Experiment No. 6. — At that same station and in as limited a time as practicable take temperatures at 150, 
300, and 500 fathoms, by a separate haul for each depth, without stopping on the ascent. Then with the same 
instruments take temperatures simultaneously at the same depths by using a separate thermometer, attached to 
the same rope, for each depth; this will require stoppages both in paying out and in hauling back for the pur- 
pose of attaching and removing instruments. 

Beport. — "Taken separately at 150 fathoms : Instrument No. 4, 68°; instrument No. 5, 67°.5; instrument 
No. 6, 68°. 

"Same at 300 fathoms: Instrument No. 4, 54°. 5; instrument No. 5, 54°; instrument No. 6, 54°. 5. 

"Same at 500 fathoms: Instrument No. 4, 46°. 5; instrument No. 5, 46°. 5; instrument No. 6, 46°. 5 

"Taken simultaneously: At 150 fathoms, instrument No. 4, 75°. 5; at 300 fathoms, instrument No. 5, 
59°.5 ; at 500 fathoms, instrument No. 6, 64°." 

During the course of the experiments the vessel was pitching moder- 
ately. 

The difference between the indications obtained at the separate casts 
in experiments Nos. 3 and 4 may have been partially due to the inclination 
of the line caused by the drifting of the vessel, the ''Eagre " having no steam. 

Experiments Nos. 5 and 6 show that a stoppage during the ascent is 
inadmissible, and that the thermometers must not be used collectively, 
in the sense in which I have employed that term. 

In experiment No. 6, at the separate casts, instrument No. 5 gave a 
temperature 0°.5 lower than instruments Nos. 4 and 6, both at one hun- 



118 DEEP-SEA SOUNDING AND DEEDGING. 

dred and fifty fathoms and at three hundred fathoms. Since all had agreed 
in the first and second experiments, it is highly probable that instrument 
No. 5 was somewhat defective in its construction, and that the column of 
mercury did not break at precisely the same point in the tube each time 
on reversal. Surgeon Jerome H. Kidder, U. S. N., assigned to duty with 
the Commission of Fish and Fisheries, found this defect in one or more 
of Negretti & Zambra's thermometers, but he was afterwards informed by 
Prof H. Y. Hind that the makers had given assurances of greater correct- 
ness in the latter instruments. 

It is uncertain how, in experiment No. 6, ^' taken simultaneously,'' the 
indications 75^5, 59°.5, and 64° occurred, as each instrument would have 
been expected to give an approximate temperature of the depth at which 
the last stoppage was made on the ascent — one hundred and fifty fathoms 
= 68°. Perhaps a short stoppage may have been made, inadvertently, as 
instrument No. 4 was near the surface, which would account for its indi- 
cating 75°.5. Instruments Nos. 5 and 6 evidently reversed at some inter- 
mediate point below one hundred and fifty fathoms, but not at that depth. 

Dr. Kidder found that while niost of the Negretti & Zambra deep-sea 
thermometers had been carefully calibrated, one or two notable exceptions 
occurred in his comparisons, in a single instance producing at one point 
of the scale an error as great as 2°. 

The instrument is perfectly protected against pressure so long as the 
outer casing remains intact. 



SPECIMENS, DENSITIES, TEMPEEATUEES, AND CUEEENTS. 119 



COMPARATIVE TEST OF 



THE MILLER-CASELLA AND 
SEA THERMOMETERS. 



NEGRETTI & ZAMRRA S DEEP- 



Atmy request, Prof. J. E. Hilgard had the following comparative -tests 
for sensitiveness made at the Coast and Geodetic Survey Office by Mr. W, 
Suess. 



Time. 




Time. 




Time. 






Standard. 




Miller- 
Casella. 




Negretti & 
Zambra. 














H. 


M. 




H. 


M. 




H. 


M. 








o 
















9 


24 


40.0 


9 


28 


40.0 


9 


25 


40.0 




30 


40.0 




30 


40.0 




30 


40.0 




32 
34 


50.0 
50.0 










34 


50.0 
60.0 


—3-4"' 


49.0 '" 






60.0 










60-0 




38 


60.0 




38 


58.6 "" 




38 


60.0 






70.0 




40 


67.0 






69.9 




42 


70.0 




42 


69.0 




42 


70.0 






80.0 






79.0 




45 






46 


80.0 




46 


79.5 




46 


80.0 




49 


90.0 










49 


88.5 




60 


90.0 




50 


89.0 j 


60 


89.0 




66 


90.0 




66 


90.0 


53 


90.0 


10 


00 


90.0 


10 


00 


90.0 


10 


00 


90.0 




02 






- 83.0 










04 


80.0 




04 


81.3 




04 


80.0 




06 


70.0 






74.0 










08 

10 


70.0 

60.0 




08 

10 


72.0 




08 

10 


70.0 

60.0 




12 


60.0 




12 


61.8 




12 


60.0 




14 


50.0 




14 


53.6 




14 


49.9 




16 

18 


50.0 




16 


51.1 

46.5 




16 

18 


49.9 

40.0 




20 


40.0 




20 


42.5 




20 


40.0 




24 


40.0 




24 


40.0 




24 


40.0 



The instruments used were a Casella mercurial standard (unprotected), 
No. 13416; a Miller -Casella deep-sea thermometer. No. 31488; and a 
Negretti & Zambra's deep-sea thermometer. No. 42665. 

These instruments were placed in a bath of 40°, and at 9^" 30™, when 
all had acquired the temperature of the bath, the experiment was carried 
forward. Readings were taken every four minutes, as shown by the large 
figures in the "time" columns. Immediately after each of these readings 
warm water was added in sufficient quantity to raise the temperature of the 
bath 10°. The small figures in the "time" columns show the readings of the 
several instruments at the instant the standard had acquired the changed 
temperature of the bath. After the standard had reached 90°, time was 



120 DEEP-SEA SOUKDING AOT) DEEDGING. 

allowed for the deep-sea thermometers to acquire this temperature; then, 
at lO*" 00"" the character of the experiment was changed and the tempera- 
ture of the bath was gradually lowered to 40°. The previous system of 
times and changes was adhered to, but the process was exactly reversed. 

These tests show Negretti & Zambra's deep-sea thermometer to be 
more sensitive than the Miller-Gasella deep-sea thermometer. If the former 
is as well protected against pressure as the latter, it is the better instrument 
in regard to the quality of sensitiveness. 

A STANDARD THERMOMETER FOR COMPARISON; HOW TO SELECT ONE. 

All thermometers should be compared with a standard when received for 
use on board ship, and the operation should be repeated from time to time. 

It is well to provide a standard which has been thoroughly tested by 
an expert, but, if necessary, any mercurial thermometer of first quality, 
having wide divisions, a full-range scale marked on the tube, and which 
is known to be several years old, may be made to serve for the purpose by 
carefully verifying its graduation. An old thermometer should be chosen 
in order to avoid the "elevation of the zero point" that thermometers 
undergo for several years after manufacture. 

The freezing and boiling points are the fixed points on which the whole 
graduation depends, and they may be tested with but little trouble. 

Melting ice or snow always gives the point of freezing, 32° of the 
Fahrenheit scale. Provide any vessel which will hold a good quantity of 
crushed ice, and which will admit of an unobstructed escape of the water 
from the bottom. A copper cylinder with an inverted-cone bottom, having 
a hole in the apex, may be used; or an ordinary water-cooler open at the 
top and having a spigot at the bottom will suffice. Surround the thermom- 
eter with crushed ice nearly up to the mark of 32°, and let it stand there 
for fifteen minutes in a place having a temperature above 32°, for the ice 
must be in a melting condition. At the end of this time note the height 
at which the mercury stands. The point reached is that of 32°, or the 
freezing point. 

Next the boiling point, 212° of the Fahrenheit scale, must be deter- 
mined, and this is done by placing the thermometer in the vapor arising 



SPECIMENS, DENSITIES, TEiMPERATUEES, AND CURRENTS. 121 

from boiling water. An apparatus and the method of proceeding are 
described in Ganot's Physics. The cuts and the text used herein for 
describing this part of the operation are copied from that work. 




F.— Apparatus 



THE BOILING POINT OF THERMOMETERS. 



"In both, the same letters designate the same parts. The whole of the apparatus is of copper. A central 
tube, A, open at both ends, is fixed on a cylindrical vessel containing water; a second tube, B, concentric with 
the first, and surrounding it, is fixed on the same vessel, M. In this second cylinder, which is closed at both 
ends, there are three tubulures, a, E, D. A cork, in which is the thermometer t, fits in a. To E a glass tube 
containing mercury is attacljed, which serves as a manometer for measuring the pressure of the vapor in the 
apparatus. D is an escape tube for the vapor and condensed water.* 

"The apparatus is placed on a furnace and heated till the water boils; the vapor produced in M 
rises in tube A, and passing through the two tubes in the direction of the arrows, escapes by the tubulure D. 
'J he thermometer, t, being thus surrounded with vapor, the mercury expands, and when it has become stationary 
•the point at which it stops is marked. This is the point sought for. The object of the second case, B, is to avoid 
the cooling of the central tubulure by its contact with the air." 

In the following paragraph I quote from Ganot, but have changed his 
figures to suit the units of measure adopted in this book: 

" The determination of the point 212° Fahrenheit would seem to require that the height of the barometer 
during the experiment should be thirty inches, for when the barometric height is greater or less than this quan- 
tity water boils either above or below 212°. But the point 212° may always be exactly obtained by making a 
correction introduced by M. Biot. He found that for every 0.6 inch difi'erence in height of the barometer there 
was a difference in the boiling point of 1°. If, for example, the height of the barometer is 30.4 inches, that is, 0.4 
inch, or two-thirds of 0.6 above 30 inches, water would boil at 212|°. Consequently 212|^° would have to be 
marked at the point at which the mercury stops." 



* The glass tube may be dispensed with when a barometer is at hand, if there is a free escape for the 



16 D S 



122 DEEP-SEA SOUNDING AND DEEDGING. 

In the manufacture of thermometers the tubes are first tested to 
ascertain if the bore or chamber of the capillary tube is of the same 
caliber throughout its whole length. When a tube is found to be perfect 
in this respect, it only requires to be divided into one hundred and eighty 
equal divisions (212°-32°) between the boiling and the freezing points, 
that each division may correspond to one degree of temperature; but when 
the tube is not perfect it needs to be calibrated. In this process a short 
column of mercury being introduced into the tube, the latter is manipu- 
lated so that the mercury may be moved about from place to place. The 
length of the column at different localities is marked on the tube, which is 
thus divided into sections of equal capacity, although it may be of different 
length. Each section is then subdivided, independently, into degrees. 

In selecting a standard .the instrument should be tested for calibration 
thus : Hold the tube in a horizontal position over the flame of a spirit-lamp 
so that the heat may be concentrated on the tube at a point about an inch 
or more from the end of the column of mercury, or, better, direct the flame 
to that point with a blow-pipe, observing caution. In a short time remove 
the tube from the flame, and, still holding it horizontal, give it a slight 
motion as if throwing a dart, with the small end of the tube foremost. 
This will break the column of mercury at the heated point. Move the 
detached column about as in the process of calibration, noting at each 
change in its position the number of divisions that it spans. The number 
should be the same throughout if the tube has been properly calibrated in 
the manufacture. If any discrepancies are discovered, pursue the process 
until they are localized, and note the points and the quantity of error in a 
table. When the experiment has been carried as far as the main column 
of mercury, join the two portions and again break the column, this time 
detaching a greater length than before, which will permit the examination 
to be carried to a lower point on the tube. Continue the process by detach- 
ing in this way a greater length of mercury each time, until the whole range 
of the scale has been tested and the table of errors or corrections completed. 
It is plain that the operation may be facilitated by selecting a cool place in 
which to perform it, for when the mercury stands low in the tube the first 
length detached may be moved through a great part of the tube. 



SPECIMENS, DENSITIES. TEMPERATUEES, AND CUERENTS. 123 

COMPARISON OF THERMOMETERS WITH A STANDARD. 

The graduation of deep-sea thermometers not being carried above 
130° Fahrenheit, the points on the scale that may be most accurately com- 
pared are the freezing point and that of water at about the temperature 
of the surrounding air. Any change of temperature of water under such 
circumstances would be very slow, thereby affording opportunity for a 
careful comparison. Several places having different temperatures might 
be occupied in turn, and a number of points tested in water with great 
nicety. A quiet place, free from draughts, should be selected. 

The freezing point may be fixed independently by the melting-ice 
test; but by also placing the standard in ice the subsequent process of 
comparison may be somewhat shortened. Next make a bath of ice- 
water; remove the ice and immerse therein the standard and the instru- 
ments to be compared, keeping the bulbs on the same level. Let the 
water become gradually warmer, reading off from time to time; or the 
operation may be more quickly completed by occasionally adding a little 
warm water to the bath, which must be stirred almost constantly to 
preserve an even temperature throughout. Thermometers suitable for 
standards are much more rapid in acquiring the temperature of the sur- 
rounding medium than the Miller-Casellas, 'which, by being protected 
against pressure in the manner already described, are very sluggish, 
making their comparison a slow process. 

Before reading off the Miller-Casellas the bath should be kept for a 
considerable time at the same temperature by adding ice-water or warm 
water in small quantities, as occasion may require, and stirring vigorously. 

In reading off the indications the question of parallax must be con- 
sidered, and the eye placed on a level with the top of the column of mercury. 

DETERMINATION OF SURFACE AND SUD-SURFACE CURRENTS. 

The demands of the more prominent features of the "Blake's" work 
permitted only a few observations for the determination of sub-surface cur- 
rents, but for those at the surface we observed frequently whenever work- 
ing in depths not exceeding two hundred fathoms. Preceding the current 



124 DEEP-SEA SOUNDING AND DEEDGING. 

observations, the cast for depth was made with rope, the lead weighing one 
hundred and fifty pounds. The depth of water having been ascertained, 
slack-line was payed out from the vessel, and the dinghy, in charge of the 
assistant-navigator, was lowered and made fast to the bight of the sound- 
ing-rope, after which slack-line was again payed out from the vessel that 
the movements of the latter might not influence the boat during the pro- 
cess of taking the observations. The apparatus used is shown on Plate 5. 
The peculiar shape of the cans shown on Plate 5 originated, I believe, 
with Prof. Henry Mitchell, Physical-hydrographer of the Coast and Geodetic 
Survey. The cans are made of galvanized sheet-iron, and in shape are, 
respectively, a cylinder of eight inches diameter and eleven inches height, 
and a cylinder of equal dimensions surmounted by a cone three inches in 
height. At the top of each is a small aperture. In use the aperture of the 
lower can is kept open to the entrance of water to facilitate the sinking of the 
can and to prevent it from crushing under pressure, while that of the upper 
can is kept closed by a cork, no water being admitted. For any observation 
both cans are used. They are connected by a length of sounding-wire 
(diameter .028 inch), and are so loaded with old scraps of lead or iron, 
or with pebbles, that when set adrift the lower can will sink to the full 
extent of the connecting wire, while the upper can will be submerged only 
to the base of its conical top, thus making the submerged surface of the 
two cans equal, which simplifies the problems relating to the determination 
of the sub-surface currents from the data obtained by observation. For 
observing surface currents the lower can is sunk to a depth of one or two 
fathoms, simply to counteract the effect of winds and surface-wash on the 
floating can; for sub-surface currents it is lowered to the depth at which it 
is desired to know the current, the distance being regulated by the connect- 
ing wire. To the upper can is attached a graduated line, marked for knots 
and tenths, the length of each knot being fifty and seven-tenths feet, to cor- 
respond to a time-interval of thirty seconds. Sometimes a few fathoms 
of stray-line are interposed between the floating can and the initial mark, 
the last being a white rag. Observations are made from the boat as a 
station point; those for velocity, excepting in the modification which will 
be mentioned, being made after the manner of observing the speed of a ves- 



SPECIMENS, DENSITIES, TEMPEEATURES, AND CURRENTS. 125 

sel with the log-chip. The direction of the movement of a can is obtained 
by compass bearings from the station point. 

In the "Blake's" work, if only the surface current was to be observed, 
the apparatus taken into the boat embraced one set of two cans, the gradu- 
ated line wound upon a hand-reel, and the time-glass or chronoscope. The 
force employed consisted of two men in charge of an officer. One man 
fastened the boat to the sounding-line and then held the glass or chrono- 
scope; the other got over the cans and held the reel, while the officer read, 
the divisions on the line and took the bearings. The rapidity with which 
Mr. Peck, Master, and afterwards Lieutenant Sharrer, could accomplish this 
kind of work with the little dinghy, even in moderately rough seas, was 
remarkable. We generally made use of their observations in shaping the 
course. The direction and velocity of the current would be shouted to 
those on board the vessel before the dinghy got alongside, and the course 
to be steered, allowing for the current found, was generally known by the 
time the boat was at the davits.* 

When it was desired to Observe for sub-surface currents, a cutter, 
manned by four men in charge of an officer, was used instead of the dinghy. 
A spare sounding-machine, like that shown on Plate 6, was lashed in the 
stern of the boat, and contained the sounding or connecting wire in five or 
ten fathom lengths, each length having at one end a small brass thimble and 
at the other a small snap-hook. To join the successive lengths it was only 
necessary to snap the hook of each into the thimble of its neighboring length. 
The reel projected slightly over the gunwale of the boat; in its friction-score 
was laid a simple friction -line, the standing part of which was secured to 
the bed-board. of the machine in advance of the reel, the inboard or haul- 
ing part being managed by hand. To get overboard a set of cans for sub- 
surface observation, the lower can, after being attached to the snap-hook at 
the outer end of the wire, was allowed to sink rapidly, the wire paying out 
from the reel, which meanwhile was kept under frictional control. When 
the snap-hook had cleared the reel, denoting that the can had reached the 



* When not on our sounding-lines we occasionally took current observations for navigating purposes, 
if "on soundings." By resorting to this expedient we were sometimes enabled to perform, with safety, feats of 
piloting which otherwise would have been extremely hazardous. 



126 DEEP-SEA SOUNDING AND DEEDGING. 

required depth, the reel was stopped, and the upper can, which had pre- 
viously been fitted with the graduated line, was then quickly attached to 
the submerged wire and set adrift. 

The methods of observing currents from a boat are inexact at the best, 
and are particularly so when a graduated line must be used; hence the 
mean of a number of observations should be obtained when possible. In a 
''straight current," as in a river or a canal, a measured base on shore, par- 
allel to the axis of the stream, with ranges and theodolites at each end, has 
been made use of instead of the graduated line. Electric current meters 
have also been used successfully for determining the velocity of the lower 
strata in rivers and canals, but I think no meter has yet been adopted 
which will record the direction of sub-surface currents in ocean depths.* 

There will be described under Cases I and II the methods employed 
by the "Blake" for determining sub-surface currents, one case being a 
modification of the other; also, under Case III, a better method, a descrip- 
tion of which, with special reference to spherical floats, is given in Ap- 
pendix No. 26, Coast Survey Report for 1859, page 311, by Prof. Henry 
Mitchell. It will be observed that Cases I and II do not involve the 
departure of the vessel from her station near the position of the sounding, 
even though long delayed there, while in Case III she might be required 
to temporarily abandon the line of soundings in order to pick up the boat. 
This will explain why we did not adopt the most accurate method. 

Case jr.— During the whole period of observation the boat remains 

* Mr. Clemens Herschel, civil and hydraulic engineer, has devised some electric current meters w^hich are 
favorably known. They are manufactured and sold by Buff «fe Berger, 9 Province Court, Boston, Mass. These 
meters do not record the direction. Mr. Herschel is very sanguine of the future success of meters in deep-sea 
current work. His own statements in reference to the subject are here given : 

"Electric current meters are now made in serviceable form for deep-sea observations in this country. 
They have been used in ten to fifteen fathoms on the rivers connecting the great Lakes, as detailed in the several 
reports of the Chief of Engineers United States Army, Survey of the Great Lakes, in the years 1868 to 1872; 
also, in depths up to twenty fathoms on the Uruguay, Parana, La Plata, and other large rivers in South America, 
as described in Envy's Hydraulics of Great Eivers, E. & F. N. Spon, London and New York. A skillful 
observer should find no insuperable difficulty in using them at much greater depths. Several of these instru- 
ments could also be strung on one and the same vertical guide-wire, and simultaneous observations of the cur- 
rents at different depths be taken in this manner. 

"An instrument for observing the direction of sub-surface currents at any depth is described in the Min- 
utes of the Proceedings of the Institution of Civil Engineers of London, session X875-'76, Pt, HI," 



SPECIMENS, DENSITIES, TEMPEEATUEES, AND CUEEENTS. 127 

anchored by the sounding-rope. Preceding and following the observations 
for sub-surface current, and, if necessary, at intermediate stages, observa- 
tions are made for ascertaining the surface current. Stated in general 
terms, the sub-surface current at any depth is found by first establishing, 
by observation, its relationship to the surface current, when, the latter 
having been ascertained directly by observation, the former may be de- 
duced. The observations for sub-surface currents are executed in the 
same way as those for surface current, excepting that the lower can is sunk 
to the depth of the stratum the flow of which it is desired to know, and that 
the time during which the connected cans are allowed to drift is generally 
increased to some multiple of thirty seconds, requiring a corresponding 
division of the reading of the graduated line. This increase of the time 
interval is also sometimes necessary in the observation of surface currents 
when there is a low velocity. 

While the lower can of a sub-surface set is sinking it may be succes- 
sively, under the influence of several currents, setting in different directions, 
in which case the upper can, when set afloat and released from restraint, 
will sometimes not attain a steady movement until some yards removed 
from the station point. In most instances, however, particularly when the 
lower can is not sunk to any great depth, it will be found in practice that 
the movement of the cans is so slow that the station point may be accepted 
as the point of departure of the upper can in taking up the true or resultant 
movement, and consequently the point from which to reckon the compass 
bearing and the reading of the graduated line. 

Case I is when the station point may be taken as the point of departure. 
It is assumed that the connecting wire of the sub-surface set of cans is rigid 
and vertical, and that it has no effect on the movement of the cans. The 
direction of the movement of the upper can is obtained by a compass bear- 
ing from the boat, and this, with the reading of the graduated line, is 
accepted as giving the resultant of the movements of the upper and lower 
strata, the latter at the depth to which the lower can is sunk. 



128 



DEEP-SEA SOUNDING AND DEEDGING. 



Let 'V =. velocity of the surface current = the velocity which the upper 
can would have if moving alone ; 
i'^ =z velocity of the sub-surface currents the velocity which the 
lower can would have if moving alone in a horizontal plane; 
V = resultant velocity of the upper and lower currents zz the ve- 
locity of the connected cans ; 
a = angle included between the directions of v and V ; 
a^ — angle included between the directions of v^ and V ; 
<9=_angle included between the directions of v and i'\ 
V and V are given by the readings of the graduated line ; a is given by 
the difference between the compass bearings taken at the surface and 
sub-surface observations respectively. Since Oz:za-{-a}, if a^ is found we 
readily get 9. 

If V and v^ are in the same vertical plane, Y =zh {v-\-v^). If v and v^ 
are not in the same vertical plane, V zr the half-sum of the projections of v 
and v^ on the vertical plane containing V, or 
= the sum of the projections of ^ v and J v^ 
on that plane, and the solution may be effected 
" by constructing the parallelogram of velocities. 
The method of solution by projection admits 
of greater accuracy than the means employed 
in observing, and this method practiced on board the " Blake." 

In Fig. 1 make AB = iw, ADrrV and B A D = a. Completing the 
parallelogram A, B, C, D, we get the side A Cr= i i;\ and the angle BAG 




Fig. 2. 




= 9; or, in Fig. 2, 
since the diagonals of 
a parallelogram mu- 
tually bisect, make 
AB='y,AE = V, and 
BAE = a. Draw B 
E and produce it to 
C, making E G = B E. 
Then A G^r-y' and B 
AC = 9. 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 129 

If it be intended to effect a solution by computation, A B = i y and 
A D = V (Fig. 1) may be referred to rectangular axes and the usual formulae 
employed, or the solution may be obtained from the two equal triangles 
of the parallelogram; since B D = A C = ? w\ and BDA:=CAD^«\ 
we have given, in the triangle A B D, the two sides A B and A D, and the 
included angle B A D, to find the side B D and the angle B D A. 

Case II. — When, at the observation for sub-surface current^ the station 
point may not be accepted as the point of departure of the upper can in 
taking up its true movement, a modification of the method described 
under Case I becomes necessary. The stray-line is dispensed with, and 
the can is secured to the graduated line at the initial point, the white rag. 
When the upper can, after having been set adrift, has attained a steady 
movement, time is noted, and a simultaneous compass bearing of the can 
and reading of the graduated line are taken at the station point. When 
the movement has continued for thirty seconds — or some multiple of thirty 
seconds — a bearing and a reading are again taken. These give the data 
for finding V and a. 

In the triangle ABC, Fig. 3, let A be the station point, B the position 
of the upper can at the first reading of the graduated line, and C its posi- 
" tion at the second reading; then, from the ^ I'ig.J 

readings and the bearings, we have the two 
sides A B and A G, and the included angle 
B A C, from which we may find the side B C = V, and also the angle A B 
C, or the angle A C B, either of which, by its relation to one of the two 
compass bearings already taken, will give the compass direction of V. 

Having Y and its compass direction, the compass direction and extent 
of V being known from observation, we readily get a, whence v^ and the 
angle 6 (Fig. I) may be found as in Case I. 

casB III. — The observations for surface current are made from a boat at 
anchor, as in Cases I and II, but those for sub-surface current are made as 
follows : Having ascertained the surface current and lowered the sub-surface 
set of cans, the latter are released without any graduated line attached. 
At the same time the boat is cast off from the sounding-rope and her course 



130 DEEP-SEA SOUNDING AND DREDGING. 

laid in the line of movement of the floating can, near which object her 
head is constantly kept, care being taken that the manoeuvring of the boat 
may not influence the motion of the can. Everything being ready, the set 
of cans used for the surface observation — with the graduated line attached, 
but without stray-line — is placed overboard as close as possible to the 
floating can of the sub-surface set and is quickly released, time being noted. 
The graduated line is payed out as necessary, and the boat constantly 
kept in her position near the floating can of the sub-surface set, as before. 
If there is any difference in the direction or velocity of the flow of the 
upper and lower strata the two sets of cans separate. At the end of the 
selected time interval the distance separating the two floating cans is 
measured by means of the graduated line, and a compass bearing of one 
can from the other can is taken at the station point, in the bow of the boat. 

This measurement gives in the triangle ABE, Fig. 2, the side B E; 
the compass bearing, together with the compass bearing taken at the obser- 
vation for surface current, gives the angle ABE. The side A B = i; being 
known, we have, in the two sides and the included angle cited, the data 
for finding the side A E = V, and the angle B A E = a. With V and a 
known, -u^ and 6 may be found as in Case I. 

When there is a swift surface current it would perhaps be easier to 
keep the boat near the floating can of the surface set, in which case the 
graduated line would have to be attached to the other floating can, but in 
the method as stated the boat's head at the time of getting over the second 
set of cans has already been laid in the direction of the movement attained 
by the sub-surface cans; hence, to follow the other set would often require 
an abrupt change of course and no inconsiderable manoeuvring. 

The difficulties in the way of accurate observation from a boat are 
evident to the nautical person. The boat is generally restless, and, when 
anchored to a long riding-scope at short stay, is liable to provide only a 
shifting station point. A bucket towed astern may lessen the swinging of 
the boat, but her instability cannot be overcome. The sinking and deflec- 
tion of the graduated line, and the oscillations of the compass-card, are 
obstacles in the way of trustworthy observations. 



SPECIMENS, DEIs^SITIES, TEMPERATUEES, AND CUERENTS. 131 

REMARKS ON THE CONDITIONS ATTENDING DEEP-SEA WORK. 

The conditions attending deep-sea work should be borne in mind in 
devising apparatus intended for the prosecution of such work. This as a 
fact seems to be self-evident, but in the observance it is not always fulfilled, 
as many of the deep-sea appliances which have been devised from time to 
time bear evidence. Some of these conditions are stated as a reminder to 
those who have had no actual experience in the work. 

Rolling ana jpitehing of the Fessei.— Thls Is au important matter to be 
considered, as has been made to appear many times in this book. 

drifting of the ¥e»sei.— Under the iuflueuce of wind or current, or both, 
a vessel will drift away from the position which she occupied at the begin- 
ning of an operation. That there are sometimes sub-surface currents to 
be encountered, and that they are frequently found to move in a different 
vertical plane from that in which the surface current moves, must also be 
considered. 

Corrosive Action of Sea-water on Metals. — By COrrOSive actlOU, if the metal 

employed in the construction of apparatus used for submarine work be not 
properly chosen, the friction of working parts may be much increased, con- 
tact of valves with their seats may be destroyed, and parts not accessible 
for cleaning may become much fouled. 

specifte Gravity of Sea-water.— It must be remembered that in sea-water 
bodies are more buoyant than in fresh water. 

Thermal j9ij(ferenccs.— lustruments lu leavlug the vessel and descending 
to deep water may be exposed to a wide range of temperature, often from 
over 100° in the sunshine to nearly 32° in the deep water. In this connec- 
tion it should be remembered that different metals or materials expand or 
contract unequally under the influence of heat or cold. In delicately- 
adjusted parts unforeseen contact or breaking of contact may result from 
much change of temperature. 

Since the lubricating oils do not retain their fluidity at a low tempera- 
ture, they should not be used to lubricate parts of instruments which are 
to be submerged in cold water. The water acts as a lubricant. 

Bydrosfatic Pressure. — The pressure ou any plane surface immersed in a 
fluid is equal to the weight of a column of the fluid whose height is equal to 



132 DEEP-SEA SOUNDING AND DREDGING. 

the perpendicular depth of the center of gravity of the surface, and whose 
base is equal to the surface pressed. 

Taking the specific gravity of sea-water as 1.026, the weight of a cubic 
inch would be .594 ounce avoirdupois. The weight of a column having a 
height of one fathom (seventy-two inches) and a base of one square inch 
would be 42.768 ounces, whence we would get the following approximate 
pressures on the square inch : 

Pounds. 

At a depth of 1 fathom 2.674 

At a depth of 10 fathoms 26.740 

At a depth of 100 fathoms 267.400 

At a depth of 1,000 fathoms 2,674.000 

Few valves will resist or retain the pressure in very deep water, 
and hermetically-closed chambers must be strong not to be collapsed. 
Material which was buoyant at the surface may become water-logged, or 
materials may be compressed until they lose their former shape. 

While many other points should be considered, according to the char- 
acter of the work or the machinery, the foregoing are some of those which 
are most prominent in importance because of their bearing on ordinary 
operations, 

STRENGTH OF SPRINGS. 

One of my chief troubles at the outset of our deep-sea work was in 
getting any information concerning springs for mechanical uses ; even the 
workmen who made springs apparently knew little more concerning them 
than was to be obtained by experiment in each individual case. 

The use of springs for delicate mechanical operations at sea should 
be avoided as much as possible, particularly if the instrument with which 
they are employed is intended to be submerged, for the springs will then 
undergo considerable change of temperature and sometimes much rough 
usage. The action of springs in air certainly does not furnish a true 
measure of that which they have in mud. 

If a flat or sheet spring be used, its broad surface, or the surface 
which is at right angles to the plane of flexure, should not be presented 
to the resistance of the water in its movement through it, unless the effect 
of such resistance on the flexure of the spring be taken into account. 



SPECIMENS, DENSITIES, TEMPERATURES, AND CURRENTS. 133 

The following is copied from Principles of Mechanics, by W. J. Miller, 
C. E., London, 1874; E. & F. N. Spon : 

"A spring being a bar of metal in a coiled form, when weights are applied either to compress or extend 
the coil, we have a corresponding compression or extension of the metal, and, tlierefore, this change of figure will 
be directly as the weight or force W applied, and directly as the number of cdils. Let N = ninnber of coils, D = 
mean diameter of coil, and rf = side of wirr if s,|uaiv .-nKl dinnirtci- if round (idiind stc..] is usually preferred by 

engineers, as the square form is apt to n-M-k at fli li^vs ilmini;- .■(.ilin-) ; then cloiiL'atidu or c()ui])ression = W X 

N. If we now vary the diameter, and consider similar parts of such ditfcrcnt sized coils as beams undergoing 
bending, we may apply the formula for the deflection of beams already given. We shall thus have tlie elonga- 
tion or compression directly as W X N X D^. 

"Again, if tlie section of metal be varied, and if we still consider part of the spring as a beam, we have the 
deflection or change of curve as bXcP (6 = breadth), or, in this case, since b = d, as rf^ and, therefore, the 
elongation or compression of the coil will be inversel^v as d'', and the formula will, tlierefore, be — 

Elongation or compres 

C ^ a constant determined by experiment. 
"If the diameter and thickness of wire be expressed in inches and the weight in pounds, ther 
from experiment that for steel springs of square section — 

C= 1 • 

2,200,000' 



^ — 1,470,000 
the elongation or compression being obtained in inches," 



CHAPTER V AND APPENDIX. 

DKEDGING AND TRAWLING; APPARATUS AND METHODS. 

FITTING THE " BLAKE " FOR DREDGING. 

On the arrival of the " Blake " at New York, in July, 1877, following 
the close of a winter season in the Gulf of Mexico, it was announced by 
the Superintendent of the Coast and Geodetic Survey that a part of the 
winter season of 1877-78, in the Gulf, would be given up to dredging, for 
which purpose Prof. Alexander Agassiz would be associated with the Coast 
Survey party. Professor Agassiz had recommended the use of steel-wire 
rope for dredging, and his recommendation had been approved by the 
Superintendent. 

The " Blake's " party organizatioh for the purposes of deep-sea work 
had existed for five years continuously : two years under the command of 
Commander J. A. Howell, U. S. N., and three years under my command. 
Since under the liberal control of the Superintendent, the arrangements of 
the vessel for the work in which she was engaged had been made very 
complete, and the party on board had become experienced in the conduct 
of most deep-sea operations, opportunity was offered for undertaking dredg- 
ing at much less trouble and expense than would have been possible with 
a new organization. There was needed for the dredging operations the 
direction of a capable naturalist, which was secured to the full in the serv- 
ices of Professor Agassiz ; but, for the vessel, only such additional appa- 
ratus was necessary as belonged strictly to a dredging outfit. 

The adoption of steel-wire rope, although presenting to our minds at 
the outset a few difficulties, which we confidently expected to overcome 
after a short experience, simplified matters as compared with what had 
previously been thought proper in a dredging outfit. Before that time 



Plate 24. 
u. s. coast survey. deep-sea sounding and dredginc. 




THE "BLAKE" AT THE WASHINGTON NAVY YARD. THE DREDGING GEAR READY FOR WORK. 
Heliotype Printing Co., 220 Devotishire St., Boston 



DREDGING AND TRAWLING— APPAEATUS AND METHODS. 135 

dredge-ropes had been of hemp or manila, and usually, for deep work, a 
tapering rope of three inches, two and a half inches, and two inches in 
circumference had been employed. The size of the steel rope selected for 
our work was one and one-eighth inches in circumference throughout its 
whole length. 




^7Wv^ 



G. — COMPAKATIVE 



Professor Agassiz and his indefatigable associate, Mr. S. W. Garman, 
did everything pertaining to their own special work as naturalists, and in 
addition accepted a share in fitting the vessel. In the division of work 
agreed upon. Professor Agassiz provided the dredges, trawls, tow-nets, &c., 
while the Coast Survey party planned and placed on board the means for 
working the wire rope. In its several stages of progress the preparation 
of the vessel was reported to the Superintendent for sanction or improve- 
ment, and as a rule our plans were also submitted by me to the valuable 
criticism and suggestions of Professor Agassiz. 

The dredging cruise of the ensuing season (1877-78) having proved 
successful, and having demonstrated the efficacy of the steel rope so 
opportunely recommended by Professor Agassiz, the vessel was refitted to 
continue the dredging work on a second cruise during part of another 
winter season (1878-79). 

Improvements were made in dredges and trawls during the first cruise, 
and a practical experience gained which suggested improvement or modi- 
fication in the method of operating the wire rope. On the completion of the 
second fitting of the vessel for a dredging cruise and the regular party 
work to follow. Commander John R. Bartlett, U. S. N., succeeded to the 
command. For this second preparation, the duties were divided between 
the naturalists and the Coast Survey party precisely as before, Professor 
Agassiz adding to his own special duties as naturalist the supervision of 
the manufacture of trawls and dredges, this time after the improved forms, 



136 DEEP-SEA SOUNDING AND DEEDGING. 

and the party on board, under the control of the Superintendent, devising, 
purchasing, and putting in place the system of machinery necessary for 
conducting the work. 

In the operations at sea, the management of the vessel and of the 
machinery was in charge of the Naval Assistants, but no dredging was 
undertaken excepting in localities indicated by Professor Agassiz, he being 
the recognized director of the dredging operations. Although a division 
of duties was necessary, no stiff lines were drawn, but all exercised a 
common interest in the conduct of the work and in the improvement of 
details. When the work of each dredging cruise had been completed, and 
the naturalists had left the vessel, the regular work of the party, consisting 
of observations for depths, serial temperatures, currents, densities, &c., was 
resumed in charge of the naval officers, this work in each case occupying 
several months after the close of the dredging operations. 

In the course of the present chapter the methods of each dredging cruise 
will first be explained, and this will be followed by detailed descriptions 
of apparatus as finally approved and adopted. There will also be given in 
the appendix to this chapter descriptions of a few of the appliances used by 
the United States Commission of Fish and Fisheries. The appendix was 
written by Prof. A. E. Verrill, and I am enabled to publish it through the 
good offices of Prof. Spencer F. Baird, United States Commissioner of Fish 
and Fisheries. In selecting from the material placed at my disposal by 
Professors Baird and Verrill, only those things have been chosen which, as 
it seemed to me, might in one way or another have proved a desirable sup- 
plement to the outfit of the " Blake." It is not thought consistent to depart 
so widely from the title of this book as to include all the valuable appli- 
ances of the Commission. 

In letters to the Superintendent of the Coast and Geodetic Survey, 
which have been published as Bulletins of the Museum of Comparative 
Zoology at Harvard College, Cambridge, Mass., Professor Agassiz has set 
forth the valuable results obtained in his department of science by the 
dredging cruises of the ''Blake." 

The heliotype views show the vessel prepared for the second dredging 
cruise, excepting that in some of them the experimental Sigsbee sounding- 



DKEDGING AND TRAWLING— APPARATUS AND METHODS. 137 

machine — which soon after these views were taken was rephice(t by the 
later form of the same machine (Plate 8) — is still in position. 

THE FIRST DREDGING GRUISE. 

(Figs. 1 and 2, Plate 29.) 

AppatatuH ami Methods. — III preparing the vessel for this crnise it was 
agreed, owing to the somewhat experimental nature of the work and the 
short time allotted for its execution, that the expenses should be restricted 
to the lowest figure; consequently the main hoisting-engine, although of 
doubtful power for very deep work, was fitted with a winch-head and con- 
tinued in use. The trouble to i^e feared with the steel rope was kinking, 
but from motives of economy a considerable risk was knowingly taken in 
this respeci. in adopting the plan by which we first worked the dredge-rope. 

There were provided but two lengths of the steel dredge-rope, each 
being 3,000 fathoms. One length was kept on a large iron reel, B, which 
was mounted on standards and controlled by a friction-brake. The reel 
was the same that is shown on several of the plates, but on this cruise it 
was operated by hand-cranks, and the friction-lever was on the after side. 
A swinging-boom, D, provided with topping-lift and guys, was mounted on 
the foremast by means of a band and goose-neck. At the outer end of the 
boom was a large iron snatch-block, G, hooked to a pendant that connected 
with an accumulator or dynamometer. The pendant' rove through a small 
iron leading-block of extra strength permanently secured at the boom end; 
thence over a sheave in the heel of the boom, whence it was made fast to 
the accumulator, the latter at the outset being laid on the upper side of the 
boom, and afterwards, as being more favorable to its proper action, sus- 
pended from the mast-head. The positions of the several independent 
parts of the dredging apparatus are very well indicated by the plans on 
Plate 29 and by the heliotype views. 

In paying out (Fig. 1), the dredge-rope passed directly from the reel 
through the pendant-block, under frictional control at the reel. For hauling 
back (Fig. 2), it was tirst stoppered abreast the pilot-house k, then slacked at 
the reel and led through a second large iron snatch-block, C, forward of the 
reel and abreast the winch-head of the hoisting-engine. With the bight of 
18 D s 



138 DEEP-SEA SOUNDING AND DEEDGING- 

rope formed between the deck-block and the reel eight or nine turns were 
taken around the winch-head of the engine. This operation completed, 
the cranks of the reel were manned, the strain on the rope taken up 
by the engine, stoppers ''come up," and the rope brought in at a rate 
varying from one minute to six or seven minutes per one hundred 
fathoms, according to circumstances. As the rope, while coming in, 
passed off the winch-head it was wound " hand taut " upon the reel. 
For the purposes of winding and guiding, a guy-rope was used, one end 
of which was made fast to the vessel's rail, the other end being turned 
over an iron thimble through which the dredge-rope was always kept 
rove. For stoppers, several long lengths of sennit were used. The sta- 
tions of men are shown by crosses on the plate. The objectionable 
feature of this method of winding the wire rope was in taking turns 
around the winch-head "07i the bight,'' which, by twisting the rope, pro- 
moted kinking. Watchfulness and care were necessary, but exercising 
these we were able to avoid kinks, excepting at the outer one or two 
hundred fathoms, where a kink was perhaps an advantage rather than 
a drawback. Kinks were easily straightened out, but they left the rope 
less strong than before. 

At our first attempt with the dredge we were brought to grief by an 
indescribable tangle of the outer two hundred fathoms of the dredge-rope, 
which happened in this wise: The rope had been payed out rapidly, the 
vessel backing slowly meanwhile and drawing the rope ahead; the large, 
insufficiently-weighted dredge having met with more resistance than the 
compact and heavy steel rope, the bight of the latter had landed first, and 
the outer two hundred fathoms of the rope, still descending, had gone 
down upon its own parts in confused coils. 

This we afterwards came to consider a most fortunate and timely acci- 
dent, for, it having taught us how to lower the dredge, we did not again 
meet with a like trouble during the whole progress of the work. There- 
after the dredge, more heavily weighted, was lowered with the submerged 
rope kept vertical and under strong tension until the bottom had been 
approached to about fifty fathoms, when the rate of paying out was dimin- 
ished and the vessel slowly backed until the dredge took ground, after 



DEEP- SEA SOUNDING AND DREDGING. 



\l S COAST S URVE Y. 




FjGIPLAN of trawl as FTKS'I' VSl'l' ON BOAT-li! TME ■BLAKE'.' 
FIG.2.PLAK OF TRAWL AS l-MPROVED BY PROFESSOR ACASSIZ. LJFU'I'. COMDR. SXGSBE.E AND ITEUT . 



DREDGING AND TRAWLING— APPARATUS AND METHODS. 139 

Avhich the rate of paying out was increased and the vessel backed accord- 
ing to circumstances, the rope always heing kept well taut. 

The extent to which the boom was topped up for work is shown on 
Pkites 24 and 30. A sounding, and an observation for bottom tempera- 
ture, preceded the dredging operations at each station occupied. 

For lowering the trawl, with its heavy iron frame and long, pendent 
bag, a different method was adopted, as suggested by consideration of 
the unequal resistances encountered by the parts mentioned in passing 
through the water, it being necessary to guard against the bag getting 
up over the frame-work. With the end of the bag well weighted, the 
trawl w^as payed out cautiously, the vessel backing slowly to keep the 
rope tending slightly ahead. As the trawl neared bottom the reel was 
stopped for several minutes, while the backing of the vessel was con- 
tinued. Then the w^ork of paying out was resumed until the trawl had 
landed. Our method in this respect increased the probability of plant- 
ing the trawl fairly on its runners and of keeping the rope taut at a 
critical moment. 

The steel dredge-rope when held in the hand always gave the most 
decided indications of the 'dragging of a dredge or trawl along the bottom, 
and as soon as the implement was felt to be "biting" the additional scope 
of dredge-rope thought necessary was payed out as desired by backing the 
vessel and regulating the friction at the reel. 

No weights were used on the steel rope in advance of the dredge or 
trawl, as is necessary when the rope employed is of hemp or manila. The 
weight of the steel rope alone was found to keep the implement flat. 

The length of rope payed out, whether for dredging or trawling, gen- 
erally followed this rule: In depths no greater than three hundred and 
fifty fathoms, equal to twice the depth of water; in depths exceeding that, 
one-third greater than the depth of w^ater. 

A tackle from the forward .part of the swinging-boom was used for 
hoisting the dredge and its contents over the rail to the deck, but the trawl, 
being unwieldy, was first swung abreast of the fore rigging by means of a 
mast-head tackle, from which position it was hoisted until the frame had 
cleared the vessel's rail, when the netting was gathered aboard by hand. 



140 DEEP-SEA SOUNDING AND DEEDGING. 

Professor Agassiz suggests the use of a light gaff on the forward part of 
the foremast for this purpose. 

It has been stated that the dredge and the trawl were improved during 
the first dredging cruise; in what respect will now be shown. Those with 
which we fitted out are illustrated in Fig. 1, Plate 25, and Fig. 1, Plate 26, 
respectively. Early in our work it was noticed that the dredge gave but 
few specimens of animal forms from soft bottoms, even when it came up filled 
with the bottom material. This material being ordinarily of a moderately 
tenacious character, requiring a long-continued manipulation to force a 
quantity of it through a sieve in water, it was supposed that the dredge on 
reaching bottom soon became surcharged with the mud or ooze, and that 
very little washing out through the netting taking place thereafter, other 
matter was excluded after the first few feet had been traversed. Additional 
evidence on this point was afforded by the profusion of specimens brought 
up on the tangles from the same localities, and also by the disproportion- 
ately greater number obtained in the trawl as compared with the dredge. 
The opinion was broached early in the work that the dredge should skim the 
ground rather than plow into it, and in its form should partake of the char- 
acteristics of both the dredge and the trawl. Although this view was op- 
posed to previous practice. Professor Agassiz thought it worth submitting 
to experiment. Accordingly, Master H. M. Jacoby and the writer improvised 
a dredge which would not plow, and it proved so successful at the first ven- 
ture that afterwards, at Key West, a drawing was prepared from which an 
improved dredge, as shown in Figs. 2, 3, and 4, Plate 25, was constructed. 
The new dredge was used thereafter with much better results than we had 
met with in the use of the old dredge. With the former more than thirty 
hauls were made, some of them oh very soft bottom, but in only two or three 
instances did it bring up more than several handfuls of mud or ooze, 
although by lining the bottom of the bag with closely-woven stuff, bottom 
material in considerable quantity might nearly always have been obtained. 
It is evident that the improved dredge, without the special lining, collects 
the material of soft bottoms in such small quantities that the much-desired 
washing through the netting of this material in the process of dragging 
actually takes place. 



PLATE 27. 



U. S. COAST SURVEY. 



DEEP-SEA SOUNDING AND DREDGING. 




THE IMPROVED TRAWL READY FOR USE. SEE FIGURE 2, PLATE 2 
Heliotype Printing Co., 220 Devonshire St.. Boston. 



DEEDGING AND TRAWLING— APPARATUS AND METHODS. 1.41 

With the style of trawl that had previously been used for deep-sea 
work it was essential to success that it should land fairly on its runners ; 
that is, with the beam uppermost. Although it would land as desired in 
most cases, yet experience had shown repeated failures, and a failure in 
deep water involved the loss of much time and the risk of valuable gear 
without compensation. 

Professor Agassiz, Lieutenant Ackley, and the writer, in the course of 
a conversation, each offered suggestions until we had succeeded in draw- 
ing up a rough design for the trawl shown in Fig. 2, Plate 26, and also on 
Plates 27 and 28, and we afterwards had much reason to be gratified with 
the working of the improved implement. 

THE SECOND DREDGING CRUISE. 

(Fig. 3, Plate 29.) 

Apparatus and jiethoas. — The first dredging cruise having established 
beyond doubt the superiority of steel rope over hemp or manila for dredg- 
ing purposes, the Superintendent authorized a more complete outfit for 
the second cruise. 

Fig. 3 shows the method of working the dredge-rope during this 
cruise. The reel B, containing the rope, was the same that had previously 
been used, but it was reversed to bring the brake-lever on the forward 
side, and was provided with a small double-cylinder reversible steam- 
engine, E, for winding the wire. The lead of the rope was as follows: 
From the reel it followed the course of the dotted line, passing through the 
several iron snatch-blocks G, C, Sec, eight or ten turns being taken around 
the winch-head of the hoisting-engine A. This was the lead of the rope, 
both for paying out and for hauling back; there was no need to take 
turns around the winch-head "on the bight" as before, and thus the rope 
could be kept constantly under tension, which is almost a necessity in 
working wire rope. The fleet aft, from the reel B to the first block C, was 
a long one, rendering it easy to guide the wire evenly on the reel when 
hauling back. The swinging-boom and its fittings were the same as before, 
excepting that a new accumulator, or dynamometer. Fig. 3, Plate 34, was 
provided. The new hoisting-engine A was very different from that for- 
merly used. On the latter the winch-head was permanently connected with 



142 DEEP-SEA SOUNDING AND DEEDGING. 

the crank-shaft by gearing, and could not be worked independently of the 
engine. 

The new engine (Plate 33) will be more fully described hereafter, but 
it is necessary to give some idea of it at this point in order to explain 
clearly the operation of dredging during the second cruise. 

The winch-head, which over its smallest circumference exactly accom- 
modated one fathom of the rope in a single turn, was fitted with a friction- 
band, the lever for which could be instantly locked in position, either when 
the friction-band was out of contact or when binding with full force. By 
means of a clutch and lever, the latter fitted to lock in position, the winch- 
head could be connected or disconnected from the engine at will. A 
worm on the hub of the winch-head was made to engage the gears of a 
counter or register such as was used on the sounding-machine. By this 
means, due to a timely suggestion by Lieut. W. 0. Sharrer, it was no longer 
necessary to mark the dredge-rope; the counter gave the length of rope 
out with a percentage of error too small to be of consequence in dredging, 
for the exact depth was always first ascertained with the sounding-machine. 
All appliances for controlling the engine were placed on the starboard side, 
and one man standing on that side, as shown by the cross on Fig. 3, per- 
formed five duties — viz, to attend the throttle, the friction-lever, the clutch- 
lever, the reversing-lever, and to read the counter. 

At the dredge-reel the arrangement was similar; the man standing at. 
that point attended the throttle, the friction-lever, the clutch-lever, and the 
reversing-lever. In addition, he could guide the rope on the reel in case 
of emergency. 

The drawings for the hoisting-engine were made by Mr. Earle C. 
Bacon, of Messrs. Copeland & Bacon, 85 Liberty street, New York. I 
stated to him the size of cylinders, relation of gears, the action required 
of the several parts, the positions of levers and throttle — in general terms 
the requirements; and he then worked the whole out in his own way — no 
easy matter, as may easily be seen — using his patent trunk-cylinders ; and 
so successful was he in the design that not a single fault has been found 
with his engine by those who have used it. He worked out the form of 
the winding-engine at the reel, and with the same success. 



U. S. COAST SURVEY. 



PLATE 28. 



DEEP-SEA SOUNDING AND DREDGING. 




THE IMPROVED TRAWL SHOWN AS HAVING "TRIPPED" AFTER FOULING WITH ROUGH BOTTOM. 
Heliotype Printing Co., 220 Devonshire St., Boston 



DREDGING AND TRAWLING— APPARATUS AND METHODS. 143 

On this cruise the methods adopted for planting the dredge and trawl 
were practically the same as on the previous cruise, but as regards the 
working of the machinery and gear Professor Agassiz and Commander 
Bartlett state that the drawbacks which had been experienced before were 
not met with at all. The work proceeded smoothly, and without accident 
which could in any way be laid to the agency of the machinery. The 
rope could be wound upon the reel wath nice regularity. 

The operation of paying out rope was managed as follows : the dredge 
or trawl being shackled to the rope and over the side, the counter set, 
the friction-brake at the reel in hand, and the engine at the reel out of 
gear, the brake at the hoisting-engine was thrown out of action and 
locked; the winch-head was clutched to the gears and the link adjusted for 
reversing the engine. In this state everything was ready. The weight of 
the dredge or trawl alone not being sufficient to overcome the various 
resistances opposing the movement of the rope, it was necessary to pay out 
with the hoisting-engine until the weight of several hundred fathoms of 
rope had been added thereto. All that was required to start the operation, 
after the preparatory measures already described, was to open the throttle. 
When the submerged weights were sufficiently heavy to overhaul the rope, 
the throttle was closed and the winch-head unclutched from the gears. 
The friction-brake at the reel needed careful attention, particularly when 
the hoisting-engine was turning over, for the latter was powerful enough 
to part the rope, while the former could give a resistance much beyond the 
breaking strain of the rope. 

In dragging, the strain was taken at the winch-head, controlled by the 
brake, backed, if necessary, by the brake at the reel. 

For hauling back, the winch-head and the reel were thrown into gear 
with their respective engines, and the links of each engine adjusted for 
winding up the rope. The brake at the reel was secured out of action, and 
the throttle of the winding-engine was then opened slightly. As nearly as 
possible at the same time steam was turned on at the hoisting-engine and 
the brake on the winch-head locked out of action. Afterwards the speed 
of the winding-engine was regulated to suit that of the hoisting-engine, 
the object being to keep the rope taut between the two engines in order to 



144 DEEP-SEA SOUNDING AND DEEDGING. 

avoid kinking, and at the same time not to wind it upon the reel under so 
severe a tension as to accumulate a great crushing force upon the drum or 
barrel of the reel. 

After our first dredging cruise it was the general opinion on board 
that, in dredging, an accumulator was not a necessity, excepting as a 
dynamometer and to give a slight elastic cushioning. A critical moment 
in dredging is when a dredge or trawl which has fouled with the bottom 
is in the usual position for breaking ground — that is, when the rope is 
vertical and under great strain. At such a time it is desirable to know 
the condition of affairs below, and this a dynamometer will show, although 
after a short experience a person can form a correct judgment by holding 
the rope in his hand. When the dredge is foul, it must generally be broken 
adrift by strain, not by cushioning. Sometimes, however, a little man- 
oeuvring of the vessel over the rope may serve to clear a foul, and then 
cushioning is desirable. When dragging, the change in form of the 
catenary of the rope gives the effect of an accumulator. The "Blake's'' 
accumulator was capable of extending about six feet, and this was found 
to give ample cushioning. The deepest haul made by the vessel was in 
2,400 fathoms. 

During this dredging cruise the trawl was still further improved in a 
manner which will be explained in its proper place. 

On the first dredging cruise tow-nets had been used only at or near 
the surface, because Professor Agassiz had but little confidence in the value 
of the tow-net as it had generally been worked in deep waters — i. e., with 
the mouth wide open during the several processes of lowering, dragging, 
and hauling back. The exact habitat of specimens brought to the surface 
in this way was thought to be very much in doubt. The desirability of 
having a tow-net which could be kept closed in lowering and hauling back, 
and yet be kept open when dragging, was several times the subject of con- 
versation on board. I suggested something of this kind: the net to be 
fastened to the dredge-rope and lowered with the mouth closed; when 
dragging, a weight to be sent down on the rope, which would open the tow- 
net and at the same time detach itself and fall clear; when ready to haul 
back, a second weight to be sent down to close the mouth of the net. This 



DEEP- SEA SOUNDING AND DREDGING. 
U. S COAST SURVEY. Pl.ATF, 




PLANS OF THE DECK AND APPARATUS OE THE "BLAK-E I' 
FIG'S.l ,^2. DURING THE FIRST DREDGING EXPEDITION. 
F1G.3. DURING THE SECOND DREDGING EXPEDITION. 



DREDGING AND TE A WLING— APPARATUS AND METHODS. 145 

is a vague suggestion, but it might perhaps be put in mechanical shape.* 
On the second dredging cruise an open-mouth tow-net was tried in deep 
water, but not with much success in getthig specimens. 

Another device, called the tangle-bar drag, for dragging along the 
bottom, was used on the second cruise. It was towed by a bridle, and 
had sAvabs secured along its whole length. This apparatus brought up 
specimens in great profusion. 

GENERAL REMARKS. 

The advantages gained by the use of wire rope for dredging purposes 
are chiefly in the following particulars: compactness, strength, durability, 
neatness, facility of handling with a small force, celerity of operations, 
and economy. 

The duration of the dragging-interval was made much shorter in the . 
"Blake's" work than had previously been the practice. In the greater 
depths, where more time was consumed in lowering and hauling back, a 
longer interval was usually allowed than in depths less than five hundred 
fathoms. This restriction of the dragging-interval was perhaps a natural 
consequence of the increased facilities gained in dredging with wire rope, 
but it seems a reasonable way of working from other points of view. A 
first haul will generally indicate, to some extent, the fertility in specimens of 
the bottom that is being worked, whence barren ground may be abandoned 
or rich ground worked exhaustively. The longer the dredge or trawl is 

* An apparatus for this purpose, which has recently beau devised by the writer, at the request and with 
the assistance of Professor Agassiz, has now been made by authority from the Superintendent of the Coast and 
Geodetic Survey. It will be tested during the coming summer, aud doubtless will be published afterwards, 
with such improvements as experience may suggest to Professor Agassiz, under whose direction it will be used 
Our plan is to trap the specimens by giving to a cylinder, covered with gauze at the upper end and having a 
Hap valve at the lower end, a rapid vertical descent between any two depths, as may be desired; the valve 
during such descent to keep open, but to remain closed during the processes of lowering and hauling back with 
the rope. Au idea of what it is intended to effect may be stated briefly thus: Specimens are to be obtained 
between the intermediate depths a and h, the former being the uppermost. With the apparatus in position, 
there is at a the cylinder suspended from a friction clamp in such a way that the weight of the cylinder and its 
frame keeps the valve closed ; at h there is a friction buffer. Everything being ready, a small weight or messenger 
is sent down, which on striking the clamp disengages the latter and also the cylinder, wliin messenger, clamp, 
and cylinder descend by their own weight to h with the valve open during the passnge. W'lien the cylinder- 
frame strikes the buffer at 6 the valve is thereupon closed, and it is kept closed thereafter liy the ^veight of the 
messenger, clamp, and cylinder. The friction bufl'er, which is four inches long, may be I'eguUited on board to 
give as many feet of cushioning as desired. All parts are simple and strong. The size of the cylinder for trial 
is : height, two feet ; diameter, ten inches. 

April, 1880. 
19 DS 



146 DEEP-SEA SOUNDING AND DEEDGING. 

dragged the greater the probability of fouling and losing the implement 
and its contents, although the probability of fouling in very deep water is 
generally not so great as in the lesser depths. Professor Agassiz found 
that some of the more delicate specimens were much injured when a 
long dragging-period had been allowed. On the first dredging cruise, 
with the imperfect machinery then on board, we would haul as many as 
eight times in one day in depths varying from one hundred fathoms to 
1,500 fathoms. On one occasion we made a fine haul at eight hundred 
fathoms in one hour and twenty minutes, including twenty-three minutes 
for dragging. The time was taken on letting go and again when the 
dredge or trawl appeared above water. After the departure of Professor 
Agassiz from the vessel, shortly before the expiration of the first dredging 
cruise, we made in one day, between 7 a. m. and 5 p. m., ten hauls with 
the dredge off Havana in depths from fifty to four hundred fathoms. The 
bottom was rough and the dredge fouled at every haul, but no losses 
occurred, and the hauls were rich. Throughout the second cruise the 
work seems to have been done intentionally somewhat slower than before, 
but at the same time with greater steadiness. 

The following may be set down for safe work : Time per one hundred 
fathoms paying out and hauling back, three to five minutes, according to 
circumstances ; time for dragging, ten to thirty minutes, according to depth 
and the character of the bottom. The rate of dragging may be from one 
and a half to three miles per hour, according to the character of the bot- 
tom and the state of the sea. Paying out, and also hauling back after the 
dredge or trawl is off bottom, is so easily done that there is a great tempta- 
tion to work rapidly, but it should be remembered that in paying out it is 
of the first importance to plant the implement properly on the bottom, and 
that in hapling back the delicate specimens may be injured by too great 
speed. 

dredges: the old pattern and the improved pattern. 
(Plate 25.) 
The objection to the old dredge for general use has already been 
stated, but as it has hitherto been regarded almost as a standard form, 



DEEDGING AND TRAWLING— APPAEATUS AND METHODS. 147 

and in special cases would be more serviceable than that which is herein 
styled the improved dredge, a description of it is given. 

. The oia-pattern Dreage ( Fig. 1 ) . — There is a frame consisting of two 
flaring mouth-pieces of flat wrought-iron, beveled on their front edges, 
perforated with a row of holes along their rear edges, and joined to 
each other at their ends by bent wrought-iron braces. The braces 
serve also to hold the two wrought-iron arms forming the span or 
bridle by which the dredge is attached to the dredge-rope. A band of 
netting is stitched along one of its edges to the frame by means of plia- 
ble wire passed through the holes already mentioned; the free edge of 
the band is then gathered and seized so as to complete an open-mouth 
bag. Two lengths of stiff cotton canvas stitched to the frame over the 
netting form a shield for the latter when the dredge is dragging. The rear 
edges of the lengths of canvas and the bottom-seizing of the netting bag 
are stopped to a wisp of ratans, which serves also for fastening on sink- 
ing weights and swabs or tangles. One arm of the dredge is longer than 
its fellow, and to the eye of the long arm the dredge-rope is shackled. 
The eye of the short arm is seized with five or six turns of rope-yarn to 
the eye of the long arm. In the event of a foul on rough bottom endan- 
gering the dredge-rope, the rope-yarn seizing will part and allow the dredge 
to slew, an action which rarely fails to disengage it from an obstruction. 
These dredges are of different sizes, the frame of that for general use being 
about three feet wide, eight inches deep in the throat, and its length to the 
end of the bag being about four feet. 

The iniprovea jtreage (Figs. 2, 3, aud 4) . — By reasou of having flaring 
mouth-pieces,, and a flexible body composed of the bag and shield, the old- 
pattern dredge is almost sure to plow deeply into yielding bottoms. Since 
the object sought in the fashioning of the new dredge was to effect a skim- 
ming of the bottom rather than a deep penetration therein, a very decided 
departure from the form of the old dredge was necessary. 

The frame of the new dredge is a rectangular skeleton box made of 
wrought-iron. The mouth-pieces are flat, beveled on the forward inner 
edges, perforated along the rear edges as on the old dredge, and are riveted 
to the skeleton or bar-iron portions of the frame-work, in which position 



148 DEEP-SEA SOUNDma AKD DEEDGING. 

they are held parallel. The rear of the upper and lower sides of the skele- 
ton are connected by three riveted braces, the whole frame-work being- 
rigid. A tangle-bar of wood, bar-iron, or iron pipe, to carry the weights 
and tangles, has seized to it three sister-hooks, which are hooked severally 
around the braces and moused. The arms are like those of the old dredge, 
one arm being longer than the other. A netting bag and canvas shield, as 
in the ease of the old dredge, are stitched with pliable wire to the dredge- 
frame. A trap like that of the trawl is fitted inside the main bag. The 
bottom of the main bag is stopped to the middle brace at the rear of 
the frame. Each flap of the canvas shield is turned over and around its 
own side and end of the skeleton frame, and stitched to its own part with 
stout twine, presenting a tolerably smooth sliding-surface. 

DIMENSIONS OF IMPROVED DBEDGE. 

Ft. In. 

Length from moutli to rear of frame 4 

Depth between mouth-plates or flanges 9 

Widthofframe .. a 

Mouth-plates: Width 4J 

Thickness of metal | 

Distance of row of holes from rear edge J 

Distance apart of holes 1^ 

Skeleton frame, diameter of round-iron ^ 

Longarm: Length 3 1 

Diameter of round-iron f 

Shortarm; Length 2 11 

Diameter of round- iron f 

Shield (cotton canvas) . . No. 3. 

Netting for main hag and trap: Mesh (square)., i inch. 

Stuff (tarred cotton) . . ^^ thread.* 

If it be intended to bring up a specimen of the bottom material with 
this dredge, the bottom of the main bag may be lined for a short distance 
with muslin. 

THE IMPROVED TRAWL. 

(Fig. 2, Plate 26.) 

The plate shows the general plan, not the details. 

Two wrought-iron runners are connected by two wrought-iron pipes 
or beams as shown, excepting that the ends of the beams fit into collars 
which are riveted to the runners. The several parts of the frame are rigidly 

* See netting for dredges and trawls, page 154. 



DREDGING AND TRAWLING— APPARATUS AND METHODS. 149 

joined together, so that, when dragging, the runners move in parallel 
planes at right angles to the axes of the heams. An open-mouth netting 
bag, roped all round the mouth, and with the roping leaded at intervals, is 
laced along the rear ends of the runners and strongly secured to the corre- 
sponding corners. This leaves two free bights or loops of roping, one of 
which trails on the ground when the trawl is being dragged. The mouth 
of the bag should be made large enough to allow either loop that may be 
uppermost to hang as low as the beam when the trawl -is lying flat. This 
and all other netting bags described herein are made from netting pur- 
chased in long lengths or bolts. The main bag is formed from a rectan- 
gular piece of netting cut from the bolt, the raw edges being joined in a 
seam to run lengthwise on the bag. The lower edge of the band, opposite 
the moutli, is then gathered and the folds are seized together. A second 
but shorter bag, called a trap, is fitted neatly within the main bag at one- 
half or one-third the length of the main bag from the frame, forming a 
pocket of considerable size for the reception and retention of specimens, 
the only entrance or exit being through a small hole in the bottom of the 
trap so long as the bottom of the main bag is kept closed. The netting 
around this trap-hole is either roped or bound with heavy wire, the latter 
being preferable, as a rope grommet often twists into a "figure-of-eight" in 
water. From the grommet or wire hoop, as may be, several long stops 
are passed to the seizing at the bottom of the main bag to protect the trap 
against reversion. The trap may be made from a triangular piece of netting. 

In order to prevent the uppermost side of the main bag from falling 
and closing the entrance to the trap when dragging, a piece of rope some- 
what longer than the width of the main bag, and having corks strung upon 
it at intervals, is fastened by each end to the sides of the main bag, inside 
the latter. 

As thus described, and fitted with the bridle shown in Fig. 1, we 
have the trawl as improved on the first dredging cruise. Afterwards other 
improvements were adopted. . I modified the bridle, making it as shown 
in Fig. 2. The new bridle is secured to the runners at the front beam 
by lashings passed through cut-splices in the rope ; to the runners at the 
rear beam by lashings taken around the rope, and to the seizing at the 



150 DEEP-SEA SOUNDING AND DEEDGING. 

end of the main bag by lashings taken through thimbles which are turned 
into eye-splices. The function of the new bridle is to bring up the trawl 
rear end foremost in the event of severe fouling on bottom, the tripping 
being brought about by the parting of the lashings. (Plates 27, 28.) 
Fouling with the trawl we found to be a very serious matter, as it was 
sometimes impossible to clear it when using the old style of bridle. 

As used on the second dredging cruise the mouth of the main bag was 
made larger; the roping was carried forward arid made fast to the runners 
at each end of the front beam, giving a longer bight of the roping to trail 
on the ground than before; and to prevent the uppermost bight from fall- 
ing and closing the entrance to the bag a rectangular piece of netting was 
stretched between the two beams and laced to them along their whole 
length. The latter contrivance is also intended to guide certain specimens 
into the bag. These improvements are, I believe, by Professor Agassiz 
and Ensign G. H. Peters. 

Professor Agassiz added a netting jacket inside of the main bag from 
the mouth of the trap downwards. The bottom of the jacket was lined 
with four feet of a smaller size of netting, and was closed by gathering the 
folds as in the case of the main bag. 

An idea which occurred independently to Professor Agassiz and my- 
self, but which was not put ih practice, was to make the mouth of the 
main bag larger, and to reeve the roping through bull's-eyes or thimbles at 
each of the rear corners of the runners. The strain on the dragging bight 
would then gather the slack of the uppermost bight through these fair- 
leaders, keeping it clear of the mouth of the bag and lengthening the drag- 
ging bight. It would involve some little trouble to adapt the roping to 
this movement in order that the netting might not be dragged through the 
fairleaders, and that the strain on the corners of the runners caused by the 
pull of the dragging bight might not be multiplied. The following sug- 
gestion is offered for this purpose : A rope, of the same length and size as 
that used for the roping, to be rove through the fairleaders and made into 
a band; the roping of the bag to be seized to -this band at short intervals, 
excepting for a certain distance near each fairleader, where it is to be left 
free to permit the traveling of the band through the fairleaders as required. 



DEEDGING AiTD TEAWLING— APPAEATUS AND METHODS. 151 



By a careful arrangement of the end seizings of the series, the traveling 
of the band might be stopped at such a point and in such a manner as to 
avoid multiplying the strain at the corners of the frame. Toggles turned 
into the roping might also be used for the purpose. 

A comparison of Figs. 1 and 2, Plate 26, will show, without further 
explanation, the points of difference between the improved trawl and the 
trawl that we first used. 

DIMENSIONS OF STANDARD TKAWt FOR DEEP-SEA WORK, No. 1. 

Runners: Length 48 inches. 

Depth 30 inches. 

Width 3 inches. 

Thickness of metal i inch. 

Front pipe or beam : Length 10 feet. 

Outside diameter 2^g inches. 

Thickness of metal iV inch. 

Rear pipe or heam: Length 10 feet. 

Outside diameter 2 inches. 

Thickness of metal i\ inch. 

Collars on ends of teams : Length 2i inches. 

Thickness of metal } inch. 

Diameter of bolt f inch. 

Rope : For bridle (hemp or manila) . . 3 inches. 

For roping (hemp or manila) . . 2i inches. 

Main bag: Length 15 feet. 

Size of mesh (square).. 1 inch. 

Stuff (cotton).. 21 thread. 

Trap: Mesh (square).. i inch. 

Stuff. (cotton).. 15 thread. 

Jacket : Mesh (square) . . i inch. 

Stuff (cotton) . . 15 thread. 

Bottom lining : Mesh (square).. i inch. 

Stuff (cotton) . . V thread 

DIMENSIONS OF SMAUj BUT HEATY TRATTL FOR INSHORE WORK, No. 3. 

Runners : Length 30 inches. 

Depth 14 inches. 

Width 3 inches. 

Thickness of metal f inch. 

Front pipe or beam : Length 8 feet. 

Outside diameter 2 inches. 

Thickness of metal Thick. 

Rear pipe or beam : Length 8 feet. 

Outside diameter li inches. 

Thickness of metal Thick. 

Ropes and netting .' Same as for large trawl. 

DIMENSIONS OF LIGHT TRAAVt FOR DRAGGING RAPIDLT, No. 3. 

Runners: Length 1 48 inches. 

Depth, at rear end 24 inches, tapering forward to 18 inches. 

Width , 2 inches. 

Thickness of metal i inch. 



152 DEEP-SEA SOUNDING AND DREDGING. 

Front pipe or beam : Length 10 feet. 

Outside diameter 2-^g inches. 

Thickness of metal ^s inch. 

Rear pipe or beam; Length. 10 feet. 

Outside diameter 2J inches. 

Thickness of metal -?e inch' 

Ropes and netting Same as for standard trawl. 

No. 3 trawl is recommended by Professor Agassiz for rapid dragging. 
He states that they get, usually, more fishes and Crustacea. In his notes, 
from which the tables of dimensions have been mainly compiled, I do not 
find the size of the beams of No. 3, so I have made them the same as those 
of the large trawl. 

The cost Oi the ''Blake's" trawl-frames was from $17 to $20 each. 

WEIGHTING DREDGES AND TRAWLS ; TANGLES. 

When fitting out for each dredging cruise we purchased a number 
of cast-iron twelve-pound weights, which we used as sinking-weights for 
dredges and trawls. Although we were plentifully supplied with sounding- 
shot these lighter sinkers were found to be more generally useful — permit- 
ting a better distribution of weights. 

Our custom was to load the trawl with two twelve-pound weights on 
each runner and a sixty -pound sounding-shot at the end of the main bag, 
as shown on Plate 27. It is, perhaps, better and cheaper to load the 
runners in this way than to make them heavier in the manufacture. In 
the lesser depths probably no extra weight would be needed. Another 
way of loading the bag of the trawl is to string two or three sounding-shot 
on a cheap form of sounding-rod trailing from the bottom seizing of the 
bag; the shot are detached on striking bottom. This insures a good 
descent, but is expensive. 

The dredge was generally weighted with three twelve-pound sinkers 
suspended from the tangle-bar, which was of wood. Sometimes we would 
also lash a twelve-pound sinker transversely on each side of the mouth. 
We used a wooden tangle-bar that it might break if badly jammed between 
rocks. 

Four tangles were lashed to the tangle-bar of the dredge. These were 
simply large swabs of hemp rope-yarns. The length of the tangles should 



Plate 30. 

U. S. COAST SURVEY. DEEP-SEA SOUNDING AND DREDGINC. 




VIEW OF THE ■• BLAKE'S" DECK LOOKING FORWARD FROM THE BOW OF THE STARBOARD QUARTER-BOAT. 
READY FOR PAYING OUT THE DREDGE. 

Heliotyfie Pymting Co.. 220 Devonshire St., Boston 



DREDGIIS^G AND TRAWLING— APPARATUS AND METBODS. 158 

be less than that of the dredge, otherwise they may float over the mouth 
of the dredge and foul while paying out. After being picked over, the 
tangles often remain matted with sponges, broken spines, 6cc. The best 
way to clear them is by towing them overboard. 

THE TANGLE-BAR DRAG. 

The use of this implement from the "Blake" was begun on the second 
dredging cruise, at the instance of Professor Agassiz. A wTought-iron 
plate six feet long, three inches wide, and half an inch thick, Avith the 
forward edge beveled, had fastened to it at intervals along the rear edge 
a number of tangles to be dragged along the bottom. At each end and 
midway between on the front edge were eye-bolts for attaching the three 
legs of a bridle, and midway on the rear edge was another eye-bolt from 
which a sixty-pound sinker was dragged by a short length of rope. This 
drag was used with great success. I think twelve was the number of 
tangles attached to a single bar. 

TOW-NETS OR DRAG-NETS. 

Those used by us on the first dredging cruise were brought on board 
by Professor Agassiz. They were composed of a bag of embroidery 
canvas, Swiss muslin, or some similar stuff laced to a ring of brass wire 
one-fourth of an inch thick. To the ring was secured the three or four 
legs of a bridle to which the tow-line M^as bent. The nets may be of any 
dimensions desired. Ours, which were only used near the surface, were 
about fifteen inches across the mouth. 

Professor Agassiz has sent me a diagram of a large drag-net used in 
deep water on the second dredging cruise. In this the mouth-ring was 
of three-fourths-inch wTought-iron and elliptical in shape, the diameters 
being five feet and three feet respectively. The bag was of netting one- 
fourth-inch square mesh, with a lining of muslin at the bottom to form a 
pocket. Professor Agassiz remarks that they should be moved through 
the water rapidly.* 

* See foot-note, page 145. 



154 DEEP-SEA SOUNDING AND DEEDGING. 

NETTING FOR DREDGES AND TRAWLS. 

The netting for the "Blake" was purchased from the American Net 
and Twine Company, 43 Commercial street, Boston. For the first cruise 
the main bags of trawls were regularly made in the manufacture, i. e., the 
round at the bottom was made by gradually decreasing the size of the 
meshes. For the second cruise, Professor Agassiz purchased the netting 
in lengths, and the bags were made on board as described heretofore. 
Our purchases of netting for this cruise were as follows: 

For main bag of trawl : web to hang ] ,000 feet by twenty feet, mesh 
one inch square, twenty-one-thread cotton ; seven hundred and fifty-nine 
pounds, at forty-five cents per pound. 

For trap and jacket of trawl: web to hang 1,000 feet by six feet, 
mesh one-half inch square, nine-thread cotton; two hundred and fourteen 
pounds, at seventy cents per pound. 

For bag and trap of dredge : web to hang sixty-seven feet by six feet, 
mesh one-quarter inch square, ^ tarred cotton; fourteen pounds, at two 
dollars and fifty cents per pound. 

The term '^web to hang'' means when slightly stretched, as when 
attached to the roping of a seine. The meshes are measured either by the 
diagonal or by the length of one side. Thus a mesh having each of its 
four sides one inch in length is called a two-inch mesh or one-inch square 
mesh. The latter term seems to be the plainer. 

Professor Agassiz recomfnends changes in the above as follows, and these 
changes have been introduced- into the tables of dimensions already give^i: 

For main bag of trawl, web to hang fifteen feet instead of twenty feet. 

For tra^ and jacket of trawl, fifteen-thread cotton instead of nine-thread 
cotton. The difference in cost and weight is as fifteen to nine. 

TUBS AND SIEVES. 

The "Blake's"" supply of these appliances was very simple: a nest of 
sieves, from coarse to fine, and several tubs. The tubs were of thick wood, 
iron' bound, and fitted with iron handles. They were about • twenty-four 
inches high, twenty inches in diameter at the top, and somewhat less at 
the bottom. We found that these answered our purpose well for deep 




> 

W 
GO 



DREDGING AND TRAWLING— APPAR AT CTS AND METHODS. 155 

work, but in the work of the Fish Commission down only to a depth of two 
hundred fathoms, the hauls being more frequent and the specimens gen- 
erally less fragile, the special appliances shown in the appendix to this 
chapter are used with success. 

STEEL-WmE DREDGE-ROPE. 

Our rope was made at Trenton, N. J., by the John A. Roebling's Sons 
Company. It was one and one-eighth inches in circumference, and was 
composed of six strands laid around a tarred hemp heart. Each of the 
six strands was composed of seven galvanized steel wires of No. 19 Ameri- 
can gauge (No. 20 Birmingham gauge). The ultimate strength of the rope 
was 8,750 pounds,* weight per fathom 1.14 pounds in air, and approxi- 
mately one pound in sea- water; price, eight cents per foot. 

For the first dredging cruise it was supplied in 3,000-fathom lengths, 
each length wound upon a separate wooden reel. For the second cruise, 
the working reel already having 2,700 fathoms upon it, I had the rope 
supplied on wooden reels, each containing only five hundred fathoms, in 
which shape it was easier to handle in the event of having to replace losses 
at sea. One wooden axle common to all these reels formed part of the outfit. 

The shortest nip that we gave the rope was over the pulleys of the 
leading-blocks, the scores of which were eighteen inches in diameter, and 
this did not break up the zinc enough to give trouble from rusting. We 
used no preservative on the rope and had no need for it, but that recom- 
mended by the Roeblings is raw linseed-oil applied with the fleecy side 
of a piece of sheepskin, or to the oil may be added equal parts of Spanish 
brown or lamp-black. To preserve wire rope kept under water they 
recommend a mixture of mineral or vegetable tar with fresh-slacked lime 
in the proportion of one barrel of the former to one bushel of the latter; 
the mixture to be well boiled and applied freely while hot. 

At the works wire rope is reeled up under strong tension, and in reel- 
ing off for use it should be passed directly from one reel to the other under 
at least slight tension, and it never should be coiled down or faked by hand. 
When supplied in a coil, the coil should be rolled along like a wheel and 
the rope payed off in that way to the working reel. 

* Two lengths tested for strength in kinlcs gave breaking strains as follows : 4,410 pounds, 4,600 pounds. 
April, 1880. 



156 DEEP-SEA SOUNDING AND DREDGING. 

For joining two lengths of the rope a "long-sphce" should be made, 
at least twenty feet in length. To make an eye-splice at the end of the 
dredge-rope, turn the end of the rope around an oblong or heart-shaped 
thimble, and unlay each wire from the thimble to that end. Lay these wires 
as an untwisted strand along the rope and serve wires and rope together 
tightly with annealed-iron wire for a distance of eight or ten inches from 
the thimble. Cut off the free ends of the wires about three-quarters of an 
inch above the serving and turn down each wire neatly along the serving. 

The dredge, trawl, &c., should always be attached to the rope by a 
shackle. We at first used hooks which we moused with wire, but they 
always broke adrift, probably by bending. Long shackles should be 
selected, of a size to slip into the thimbles, and into the eyes in the arms 
of the dredge. I would call particular attention to this matter, hoping to 
prevent a resort to makeshifts. 

THE DREDGE-REEL, 

For dredgjng in depths no greater than five hundred fathoms, which 
would require the use of no more than 1,000 fathoms of rope on the work- 
ing reel, the latter might be made part of the hDisting-engine and be geared 
to the crank-shaft. The advantage would be in compactness and simplicity. 
For general work, the plan adopted for the "Blake" is probably better. 
When the reel takes the full strain on the rope in hauling back great 
strength is needed to resist the crushing force accumulated upon the drum, 
and to adapt a reel capable of holding four or five thousand fathoms of 
rope to this strain would involve an increase in its weight by no means 
desirable, either for paying out rope or for planting on a vessel's deck. 

The "Blake's" reel, which has held 4,200 fathoms of the steel dredge- 
rope, is best shown on Plate 32. The drum or barrel is of boiler-iron, three 
feet six inches long, two feet in diameter, and riveted to fillets on the two 
cast-iron side-plates. The depth of the flanges, above the drum, is one 
foot. The side-plates are made with spokes, but would be better if solid. 
The friction-band is of wrought-iron, lined with maple one inch thick. 

The standards are of cast-iron and are higher than need be. They 
were designed when it was intended to wind the rope by means of the 




r 
> 



DREDGING AND TRAWLING— APPARATUS AND METHODS. 157 

hand-cranks. When a steam-engine is used for winding, the reel should 
be set as low as poss-ible for security against the rolling of the vessel. 
In designing standards for a leel it must be remembered that they should 
be adapted to withstand violent jerks. The axle of the "Blake's" reel is 
of wrought-iron two and seven-eighths inches in diameter, reduced to two 
and five-eighths inches in the journal-boxes. The axle should have a 
bearing on both sides of each journal-box in order that the lateral strain 
may come upon both standards at each roll of the vessel. 

The friction-lever is of the double-acting kind; that is, both ends of the 
friction strap or band are l)olted to the lever, one on each side of the pivot. 

Neither the friction-score nor the bearing surface of the friction-band 
should be lubricated with oil. Water may be used, if necessary, to pre- 
vent the wood lining from taking tire, but it should be applied at intervals 
from the first, and not dashed on when the cast-iron reel is hot and likely 
to be cracked by a sudden change of temperature. 

The "Blake's" reel cost $225, and was made by Messrs. Gopeland & 
Bacon, of NeAv York. 

THE STEAM HOISTING AND WINDING ENGINES. 

( Plates 32, 33, and others.) 

The Hoistinu-enaine. — There are two trunk cylinders, of the pattern 
known as Bacon's patent (see Plate 18), each of ten and one-half inches 
bore and ten inches stroke, firmly secured to the bed-plate at an angle of 
45°, thereby avoiding a dead center, both being connected to the same 
crank-pin. The engine is provided with "link-motion" so that it may be 
run forward or backward or stopped instantaneously by the operation of 
the reversing lever, which is fitted to lock in three positions. By its elastic 
flexure the lever in locking is thrown into jogs cut in the flange of the 
standard against which it presses. The after lever, working in a vertical 
plane, as shown on the plates, is the reversing lever. 

The crank-shaft is single-geared to the shaft of the winch-head by 
strong spur-gearing in the proportion of three to one. The winch-head, 
which is 22.56 inches in its least diameter — to accommodate one fathom of 
the li-inch dredge-rope in a single turn — is keyed to its shaft, the latter 
working within the larger gear-wheel. The winch-head shaft is fitted 



158 DEEP-SEA SOUNDING AND DEEDGING. 

with a clutch working on a feather and operated by a lever moving in a 
horizontal plane. This lever may be locked in position by means of a 
thumb-screw. The winch-head may thus be thrown into gear with the 
engine, or it may be thrown out of gear and overhauled independently of 
the engine. The winch-head is provided with a powerful friction-brake, 
operated by a lever. On Plate 33 this lever is shown thrown up, in which 
position it is locked or latched in a jog cut in the flange of the forward 
standard, the friction-band being out of contact. One end of the band sets 
up with a screw and nut to a lug cast on the standard. The other end of 
the band is fastened by a pin to an arm projecting from the shaft to which 
the lever is keyed, the arrangement forming a toggle-joint, by means of 
which the lever is automatically locked when thrown down to its lowest 
position — that is, when the greatest stress is upon the band. The ultimate 
stress may be regulated by the screw and nut at the standing end of the 
band. This provision is necessary because the wood lining of the band 
will slowly wear away in use. 

Below the brake-lever is the throttle, the wheel of which is made 
large that it may be turned easily and delicately with the left hand when 
the right hand is engaged with the brake-lever. 

On the hub of the winch-head is a steel worm to engage the gears of 
a register like that shown on Plate 38, The register gives, approximately, 
the number of fathoms of dredge-rope payed out. 

On the after end of the crank-shaft, outside of the fly-wheel, is a small 
winch -head for general use. The crank-shaft is forged in one piece, and 
both this and the winch-head shaft are of the best wrought-iron. The 
journal-boxes, connecting-rod boxes, and link-blocks are of composition 
metal. All pins for valve-motion are of steel, and all parts of the engine 
are made extra strong to withstand violent shocks. 

" The engine may be run fast or slow according to the work to be done, 
and under the complete control of one man. 

The pressure of steam is usually sixty pounds. The exhaust leads 
into the condenser of the main engine. 

The cost of the hoisting-engine, fitted in place and in running order, 
was $1,150. 



DEEDGING AND TRAWLING— APPAEATUS AND METHODS. 159 

Tue mfi«iiii»-e«ffi»ie,— This is of the same general description as the 
hoisting-engine. It has two six-inch cyhnders and is single-geared to 
the axle of the dredge-reel. It is fitted with reversing and clutch levers 
arranged for locking in position. Engine and reel are under the control 
of one man. 

The cost, placed on board and in running order, was $485. 

THE SWINGING BOOM. 

This is so clearly shown by the heliotype views that an extended 
explanation of details is not needed. It was forty-seven feet long and 
fourteen inches in its greatest diameter. The metal fittings and fasten- 
ings were of wrought-iron. The topping-lift was of three-inch manila, 
rove through iron-strapped blocks made extra strong. The pendant was 
of 4J-inch manila. The small block at the boom-end was of a well-known 
commercial pattern, extra fastened under my direction. The pendants of 
the guys were of two-inch iron-Mire rope, and the falls for the same of 
2^-inch manila. 

THE ACCUMULATOR OR DYNAMOMETER. 

(Fig. 3, Plate 34.) 

The accumulator for dredging is made of a number of rubber buffers, 
A, A, &c., arranged for compression on a rod, B. The buffers are separated 
from each other and from the rod B by the guide-plates G, C, &c. The 
upper end of the accumulator being secured at D, and a strain applied to 
the lower end at E, the compression of the buffers will permit the cross- 
head F to travel along the rod B, and the rods G G to travel through the 
guide-plate H and the cross-head I. In this manner the accumulator 
elongates under strain, and when released from strain it is restored to its 
former length by the elastic force of the buffers. 

The buffers are three inches deep, four and a half inches Avide, and 
have a cylindrical hole through them of one and a quarter inches diameter. 
They were purchased of the New York Rubber Belting Company, of Park 
Row, New York, at a cost of about $2 each. The material of which they 



160 BEEP SEA-SOUNDIKG AND DBEDGIKG. 

are composed is known by that company as compound No. 24, the con- 
stituents of which are as follows : 

Ten pounds fine Para rubber, cleaned. 

One pound white lead. 

One pound litharge. 

One pound whiting. 

Ten ounces sulphur — about. 

Vulcanizing heat, about 260° Fahrenheit. 

The rods B and G, G, the nuts, the cross-heads F and I, and the large 
guide-plate H are of steel; the guide-plates C, G, C, &c., are of brass; all 
other metal parts are of wrought-iron. 

The guide-plates C. G, G, &c., are one-eighth inch thick throughout 
the flanges. Their hubs are made to fit loose on the rod B, but tight 
within the buffers. 

The edges of the metal around all holes in the guide-plates and cross- 
heads should be slightly beveled to obviate friction and planing. 

The rod B accommodates thirty-two buffers without compression, but 
seven more are forced on that the accumulator may not extend for a light 
strain. Neither an accumulator nor a dynamometer is of use excepting 
for a severe strain. Plates 13 and 14 show the accumulator lowered into 
view: Plates 1 and 24 show it in its proper place, suspended from the 
mast-head. It is very elastic, and seems to have answered the purpose 
for which it was intended. Its maximum extension is about six feet. If I 
were to suggest any improvement at present occurring to my mind, it would 
be to make the buffers of a compound which would offer a greater resist- 
ance to compression. 

The total cost of the apparatus was about |130. 

The only really novel feature given by me to this accumulator is the 
peculiar shape of the brass guide-plates G, G, G, &c., the hubs or fillets of 
which keep the buffers from coming in contact with the rod B when the 
buffers are compressed. 

If fears were entertained of the accumulator giving way in use, a 
toggle might be put in the pendant somewhere above the heel of the 
boom. 



DEEP-SEA SOUNDING AND DREDGING 
V. S. COAST SURVEY PEATE 34. 





Pa 



Co J 6) 



FIG'S. 1& 2. IRON SNATCH-BLOCK FOB DREDGING ROPE. 
FIG. 3 IMPROVED ACCUMULATOR FOR DREDGING. 



DREDGING AND TRAWLING— /APPARATUS AND METHODS. 161 

THE IRON SNATCH-BLOCKS. 

(Figs. 1 and 2, Plate 34.) 

These are the hlocks through which the dredge-rope leads. The pins 
or bolts A, B, C should be of steel, the sheave D of cast-iron, the side-plates 
E, E of thin plate-iron, and the flap or hook F and the straps G and I of 
wrought-iron. In the deck-blocks the side-plates are free to revolve, but 
on the pendant-block at the boom end they are pinned to the strap G, and 
are connected by socket-bolts at the points X, X, X. The socket-bolts are 
to prevent the dredge-rope from getting between the side-plates and the 
strap G. In setting up the socket-bolts care should be taken not to bind 
the side-plates against the sheave. The dimensions given on Plate 34 are 
those of the deck-blocks; the pendant-block has a sheave one inch wider. 
Plate 31 gives a view of the deck-blocks. 

21 D s 



APPENDIX TO CHAPTER V. 

DESCRIPTION or SOME OF THE APPARATUS USED BY THE UNITED STATES COMMISSION OF 
FISH AND FISHERIES IN DREDGING OFF THE NEW ENGLAND COAST. 



By Pbof. a. E. Vekrill. 



THE KAKE-DREDGE. 

This instrument was devised in 1871, by the writer, for the special purpose of 
obtaiuing deep-burrowing species of bivalves, annelids, holothurians, Crustacea, «&c. 
It can be used only on muddy or sandy bottoms, and, of course, requires considerable 
force to draw it through compact mud or sand. In its original form, which is still in 
use, it consists of a strong A-shaped frame, made of flat bar-iron, and so bolted together 
that it can be folded up compactly when not in use or for convenience in transportation. 
The rakes consist of two flat bars of iron, furnished with strong iron teeth (steel would 
perhaps be better), about a foot in length, with thin, sharp edges and sharp point. The 
two rake-bars, when in use, are placed back to back and bolted to the ends of the side- 
pieces of the A-shaped frame. The cross-bar of the A projects beyond the side-pieces, 
and has a hole at each end, by which the arms of the dredge-frame are attached, so 
that the dredge follows the rake at a distance of about two feet. The dredge-frame 
for this instrument is made entirely of round iron, and as light as is consistent with 
the stiffness necessary to support the bag full of mud when being hoisted on deck. 
The length of the frame should be equal to, or somewhat exceed, that of the rake-bars. 
In the one now used by the Commission it was originally considerably larger, but 
owing to the too great weight of the load of mud it brought up, it has been made 
smaller, so that it is now of about the same length as the rake-bars. The net is similar 
to that of the common dredge, but deeper and with somewhat larger meshes, in order 
that a part of the mud may pass through more rapidly. The vast quantity of annelid 
tubes often encountered in using the rake-dredge frequently clogs the net so as to pre- 
vent even the tine mud from passing through the meshes. As this form of dredge can 
only be used on smooth bottoms, there is not so much need of a canvas protection as 
in thje case of the common dredge, and we have often dispensed with it, but the net 
will doubtless last longer if protected with the canvas bag. 

The dimensions of the rake-dredge used by the Fish Commission are as follows : 

Indies. 

Side-pieces of tlie A-shaped frame : Length 30 

Width 2 

Thickness | 

Hole for ring | 

Bolts f 

163 



164 



DEEP-SEA SOUNDING AND DEEDGING. 




Rake-bars (d) : Length 

Width 

Thickness 

Teeth of rake : Length 

Width 

Thickness 

Ring for drag-rope : Diameter 

Size of iron 

Dredge-frame (a) : Length 

Breadth 

Length of arms 

Size of iron (round). . 
Depth of net (6) 



2i 
I 

8 

li 
I 

3i 
I 



These dimensions miglit be improved by 
making the teeth ten inches long, and at least 
one-half iucli thick if of soft iron, and they might 
have a slight forward curvature. The head pass- 
ing through the bar should be square, and about 
three-fourths of an inch thick. They might be 
fewer and farther apart without detriment — say, 
five teeth on a bar three feet long, leaving the 
spaces about six inches each. The use of steel 
of low temper would be better still. The round 
iron for the dredge-frame should be at least five- 
eighths of an inch in diameter for the size of net 
given. 

THE TANGLES. 

The original form of tangles constructed by 
the writer for theUnited States Fish Commission, 
in 1871, consisted of a bar of iron to which several 
sm all iron ch ain s were attach ed , each about fifteen 
feet in length. Along these chains, at intervals 
of about three feet, the bundles of unraveled 
hemp rope were attached, as shown in the figure. 
The bar of iron carrying the chains was attached to the cross-bar of the A-shaped 
frame forming part of the rake-dredge, the rake-bars being removed. In 1873 a fur- 
ther improvement was made by the writer. This consisted in supporting each end of 
the chain-bar in the center of a stout iron hoop or wheel by bolting it to a central 
cross-bar firmly bolted to the inner side of the wheel. The wheels are not intended to 
revolve, but merely to serve as runners and supports for the iron bar, in order to keep 
it oft" the bottom and diminish the chances of its getting caught among the rocks, as 
well as to keep it from breaking and destroying the specimens before the tangles them- 
selves can touch them. An oval or elliptical form for these runners would answer the 



-The Eake Dredge. 



DEEDGENG AND TRAWLING— APPARATUS AND METHODS. 165 

same purpose, but the circular form was adopted as the simplest, and, perhaps, the 
least liable to become caught among the rocks. In 
practice we have found the tangle-frame hitherto 
used too light for use on the larger vessel now em- 
ployed, for when rocks are encountered the chain- 
bar often comes up badly bent. In constructing 
new ones, I should recommend a round or square 
bar of iron at least twice as heavy as the one we 
have hitherto used. Our present size was first 
devised for use on a steam-launch. It was also 
used on the "Bluelight," a tug of eighty tons, with 
good success. We have used tangles of this form 
with profit on the roughest cod-fishing ledges off 
the coasts of Maine and Massachusetts, where the 
dredge could not be used with safety. It is par- 
ticularly useful in capturing starfishes and sea- 
urchins, which frequent rocky bottoms. Several 
years ago the writer suggested the use of tangles 
of this or similar form to capture star-fishes on 
oyster-beds, where they so often prove very de- 
structive. 




I.— The Tangle-Bar. 



DIMENSIONS OF TANGLES, 



Diameter of wheels outside 

Breadth of rim of wheels 

Thickness of rim of wheels 

Width of cross-bar of wheels 

Thickness of cross-bar of wheels 

Length of chain-bar 

Width of chain-bar 

Thickness of chain-bar 

Size of rings for drag-rope 

Size of iron of rings 

Size of iron of chains 

Length of iron chains , 

Length of hemp tangles 



design. 



12 inches. 
2 inches. 1 
i inch, i 
2 inches. | 
I inch. 
48 inches. 

2 inches. 
i inch. 

3 inches. 
f inch. 

i inch. 
14 feet. 
2i feet. 



14 inches. 
2i inches. 

2^ inches. 

I inch. 
60 inches. 
2^ inches. 
1 inch. 
4 inches. 

f inch. 

I inch. 
16 feet. 
3 feet. 



The drag-rope for the tangles should "be very strong, to resist the frequent and 
sudden strains when using them on rough bottoms. 



166 



DEEP-SEA SOUNDING AND DEEDGING. 



THE CHECK-STOP. 

This arrangement was devised by Oapt, L. A. Beardslee, for use on board the 
■' Bluelight," in 1873. Its piirpose is to put the strain of the drag-rope (B) upon a 

weaker rope (0), which may be so easily 
broken in case the dredge or trawl catches 
upon rocks as not to cause damage to the 
apparatus, and at the same time to give 
sufficient warning to allow the slack of the 
drag-rope to be payed out before the head- 
way of the vessel can be stopped. It has 
proved to be a very useful and simple 
expedient for these purposes. The figure 
shows the arrangement so well that no fur- 
ther description is necessary. 




THE CEADLE-SIEVE. 

This form of sieve was devised by the 
writer in 1872. It was so constructed as to 
afford the means of rapidly washing out 
the large quantities of mud often brought 
up by the dredge and rake-dredge, and at 
the same time to keep the mud and water 
off" the deck as much as possible. 

It consists of two wooden end-pieces, 

in shape forming rather more than half a 

circle, united by two narrow wooden side- 

J.— Beardslee's Check-Stop. pieces set into the end-pieces so as to leave 

a flush surface. The outside covering consists of two thicknesses of wire netting, the 

inner one with meshes of one-twelfth inch or less ; the outer one of stout galvanized- 

iron wire with one-half-inch meshes. The outer netting is only to afford support and 

protection to the inner one. The netting- 
is nailed to the edges of the wooden end- 
pieces and to the side-pieces, and is further 
secured by a strip of hoop-iron nailed over 
the edges all around. A strip of wood, 
nailed across the bottom from end to end, 
affords additional strength and protection 
from injury. Two stout iron straps, fastened 
across each end-piece by wood screws, and 
K.— The Cradle-Sieve. terminating above the edge in a ring, fur- 

nish the means of suspending this sieve against the side of the vessel outside the rail. 
The mud is then placed in it, often filling it more than half full, and a gentle stream of 
water from the force-pump is turned upon it. In this way several bushels of mud may 
be washed out in a few minutes with little trouble. Another sieve, with straight 
wooden sides about six or seven inches high— just large enough to set partially into the 




DKEDGING AND TEAWLING— APPAEATUS AND METHODS. 167 

frame of the cradle-sieve and rest upon wooden cleats, provided for that purpose — has 
been sometimes used iu connection with the cradle-sieve. Its bottom is made of strong 
galvanized-wire netting, with meshes of one-half inch. It serves to separate the 
coarser specimens and stones from the smaller and more delicate species. 

In our own work the table-sieve described below has, to a considerable extent, 
superseded the cradle-sieve. The latter is still used, however, when there is only a 
moderate quantity of mud or when the table-sieve is already full of specimens. 

DIMENSIONS OF CRADLE-SIEVE. 

Inches. 

Length 36 

BreadtH 18 

Depth 12 

Width of side-pieces 3^ 

Thickness of side-pieces and ends 1 

THE TABLE-SIEVE. 



improvements. In 



This piece of apparatus is the result of several successiv 
fundamental principle it is like 
the cradle-sieve much enlarged 
and raised on legs, but the form 
is entirely .different. 

The sieve-foundation con- 
sists of a large, rectangular, 
wooden frame (0, Fig. L), with 
wide side-pieces made of inch 
boards, supported on stout legs 
at a convenient height. The bot- 
tom of this frame consists of stout 
galvanized-wire netting with one- 
half-inch or three-fourths-inch 
meshes. Below this is a funnel- 
shaped stout canvas bag (s), 
which terminates in a large can- 
vas tube [t). This serves to con- 
duct the waste water to the scup- 
pers. A light frame of wood (B) 
is made to fit loosely inside of the L.— The Table-Sieve. 

main frame, and its under surface is covered with fine wire netting of one-twelfth-inch 
meshes. This constitutes the real bottom of the sieve, the coarse netting below serv- 
ing only as a support for it. It is fastened to a movable frame, so that it can be taken 
out and its contents emptied upon the assorting-table. This also allows the wire net- 
ting to be more easily renewed when it becomes worn. The upper or coarse sieve (A) 
is made with wide, flaring, or hopper-shaped, wooden sides, upon which, at about the 
middle, there are cleats (e, e) that rest upon the edges of the main frame. The bottom 
of the "hopper" is formed of strong galvanized-wire netting of three-fourths-inch 
meshes (Fig. M, &, b). 




168 



DEEP-SEA SOUNDING AND DEEDGING. 



DIMENSIONS OF TABI,E-SIEVE. 



Main frame : Height to upper edge 

Length 

Breadth 

Width of side-pieces 

Thickness of side-pieces . . 
Hopper-frame : Width of side-pieces 

Length at bottom 

Length at top 

Breadth at bottom 

Breadth at top. 



37 

This form of sieve, iu its primary form, was invented by Oapt. H. 0. Chester and 
the writer in 1877, but it was soon afterwards much 
improved by the addition of the canvas bag and pipe 
beneath it, which were devised by Mr. Smith, the execu- 
tive officer of the "Speedwell." 

The original use of this sieve was to receive the 
contents of the trawl, instead of emptying it on deck, 
as had been done previously ; but its advantages were 
soon found to be so great that it has also been used for 
washing the contents of the dredge whenever the quan- 
M.— The Table-Sieve. tity of mud was considerable. The legs are made of 

unequal lengths, to correspond with the curvature of the deck. 




CHAPTER YI. 

NAVIGATION AND KECOEDS. 

DEVISING A SYSTEMATIC RECORD. 

Until the records of the "Blake's" work were systematized in the man- 
ner to be described in this chapter, deep-sea parties of the Coast Survey had 
not been required to render to the office a detailed record of navigation; the 
work having been more or less desultory, there had been no general con- 
formance to a fixed system of record analogous to that demanded of inshore 
parties, and the results of the navigator's observations and computations for 
determining positions had usually been accepted as correct. On joining the 
vessel I was the bearer of instructions from the Superintendent to my pre- 
decessor in command to submit to the office, with other records, the data used 
by the navigator in fixing the positions of soundings. While Commander 
Howell was still in charge forms for computation, containing the arrange- 
ment of data shown below the headings of Forms 7, 11, and 12, were drawn 
up by Robert G. Peck, Master, one of the watch officers of the " Blake," and 
were approved by the commanding officer. The system of navigation record, 
as set forth herein, was then gradually developed during my first and second 
seasons in the Gulf of Mexico, some preliminary points having been dis- 
cussed before Commander Howell left the vessel. In the astronomical meth- 
ods employed to determine positions we made no advance; it was only in 
combining in a comprehensive system the work of navigation, plotting, and 
record, to admit of a revision of the whole navigating work at any future 
time, that we afterwards made any improvement in the department of navi- 
gation. From the impetus and scope given to the work by the adoption of 
wire for sounding purposes it followed, not unnaturally, that the arrange- 
ment of the General Record Form (Form 3), i. e., the record of soundings, 

22 D S 169 



170 DEEP-SEA SOUNDING AND DEEDGING. 

temperatures, &c., needed to be changed, and as additional forms became 
necessary we from time to time drew up and introduced all others shown 
in this book. Our efforts in this direction were, in the main, simply res- 
ponsive to the new recjuirements. 

Merely to plot a ship's positions for the times of observation is easily 
done by a navigator, but when the position of every sounding and of every 
change of the course must also be plotted, and all the processes clearly 
explained and submitted to the judgment of others, the work becomes compli- 
cated, and inevitably suggests the necessity for system to a person plotting 
in a maze of right lines, and surrounded, perhaps, by sixty, eighty, or one 
hundred Navigation Forms and other papers. While my written description 
is undoubtedly very dry reading, the system itself is nevertheless so simple 
that with the opportunity for verbal explanation it was only the work of a 
few hours to qualify a new officer reporting for assignment as executive 
and navigator. 

WHAT CONSTITUTED THE RECORD. 

On fitting out for each season the party was provided by the office with 
one or more Projections or Sounding-Sheets (Fig. 2, Plate 35) covering the 
whole ground to be worked over. They were on a scale of either .ook or 
eooVo, and on them were located all the prominent landmarks likely to be 
needed for beginning or closing the inshore ends of lines of soundings. 
The various forms used in our work were also provided as required. 

The record of the work consisted of the following: 

jFor the Coast Survey Office.— TliB General Rccord, Fomi 3, aud the Sup- 
plementary Record, Form 4, with which were bound in one volume the 
following: List of officers of the vessel, copy of the Superintendent's letters 
of instruction, diary of events, special tabulated statements, deviation 
tables, description of apparatus and methods, &c. 

The Navigation Record, Forms 6 to 12, bound in one or more volumes, 
and showing the data and methods employed in fixing the positions on the 
lines of soundings and in determining chronometer errors. 

The Sounding-Sheets, represented herein by Fig. 2, Plate 35, contain- 
ing, besides the plotted work, tabulated statistical statements of the amount 
of work done during each season. 



NAVIGxlTION AND RECORDS. 171 

Temperature Curves or Sections, Form 15. 

For the Atehivea of the Vessel. — The Original, or rougli slieets, of every- 
thing sent to the office, excepting the Sounding-Sheet, of which a tracing 
was kept. 

The Sounding Time Book, Form 1. 

The Serial Temperature Book, Form 2. 

The Plotting Form, Form 13 (B). 

The Plotting-Tracing, Fig. 1, Plate 35. 

The Rough Book of Observations, Form 5. 

EXPLANATION OF RECORD FORMS. 

For an explanation of our system, it is well to describe the record — in 
all the essential points — of some particular line of soundings, and I have 
selected for this purpose the record of a part of line S, of 1875-76, in the 
Gulf of Mexico, carrying it through one day only. As this line was run 
from South Pass, Mississippi River, to the Yucatan Bank, nearly on the 
meridian of 89°, to continue the record along the whole line would be sim- 
ply to repeat the first day so far as the purpose in view is concerned. 

As a preparatory measure an explanation of some features of the 
forms will be given. 

The General Meeord, Form 3.— ColumUS A, B, G sllOW tllC time wheU 

the sinker reached bottom, which is regarded as the time of the sounding, 
and that on which the position of the sounding should be based. 

Column D shows the serial number of the sounding, to which number 
are referred all the specimens taken at the cast. At sounding No. 10, for 
example, we obtained and saved for examination a bottom-soil specimen 
and six water specimens, all of which received the number 10, on the bot- 
tle labels. In referring any specimen to its corresponding sounding on 
the General Record, the serial number on the label would show beyond 
question — and without reference to the latitude and longitude — at which 
sounding the specimen was secured, even had two or more successive 
soundings shown equal depths. See bottle labels on page 90. 

Columns E, F, G, H are arranged to give continuity to the data 



172 DEEP-SEA SOUNDING AND DEEDGING. 

required by the draughtsman at the office in plotting soundings on the 
office sheets; that is, the data for chart-making. 

Columns I and J show the corrected water temperatures (the readings 
of the instruments and the corrections to be applied are kept on Form 2, 
page 104) . These columns are not filled by the recorder during the work 
on deck, but the entries are made afterwards when the instrumental errors 
have been applied. 

Column K shows the temperature of the water specimen at the instant 
of reading the density from the areometer in order that the density of 
each specimen may be reduced for a common temperature. The depth 
whence the specimen came is referred to the column of depths under the 
head of '^ water temperatures.'' 

Columns L, M, N, 0. — A comparison of these columns gives the whole 
time occupied at a sounding station, which it is well to know for various 
reasons, and gives also the figures for Columns P and Q. 

Columns P and Q show the time taken to make the run from the pre- 
ceding sounding or change of the course, and are of use, in connection with 
column T, in giving the officer of the deck an idea of the time required to run 
the distance from the station last occupied to the one next in order. For 
example: Master M. F. Wright relieved the deck at 4 a. m.. May 10, and, 
seeing that it had taken the vessel, in Lieut. W. 0. Sharrer's watch, 1'' 10"" 
to make 9,7 miles, from sounding No. 4 to sounding No. o, it appears that 
he allowed I'' 12"" from sounding No. 5 to sounding No. 6, hoping in that 
time to make the exact sounding-interval of ten miles. 

Column R shows at each sounding or change of the course the vessel's 
course by the standard compass from the preceding sounding or change of 
the course, and is the column to be filled by the officer of the deck, leaving 
the corrections to be applied afterwards by the navigator. 

Column S shows the reading of the patent-log at each sounding and at 
each change of the course. 

Surface currents recorded on the General Record do not necessarily 
apply to the plotting; each is obviously only the true current at one obser- 
vation spot and for one short interval of time. 

It will be seen that the arrangement of the General Record Form is 



NAVIGATION AND EECOKDS. 173 

designed to give, so far as space will permit, a general grouping of the data 
needed for scientific investigation on one page and tliat for the navigating 
purposes of the vessel on the other. 

The Supplementary Record, Form 4. — Tllis iS Of USC iu making Up the 

statistics of lines of soundings, in preparing detailed reports of operations, 
and for general reference. It shows what instruments and appliances 
were employed, and if their working was satisfactory. The categorical 
style of the headings of some of the columns was suggested by experience, 
and after its adoption we were free from ambiguities of expression, such 
as "bottom saved," "got bottom," "bottom specimen," and the like, which 
left one in doubt as to whether a specimen of the bottom had been saved 
for examination in every case or only in certain instances. 

Column F of the General Record points out, by the absence of abbre- 
viations or by special statement, if no specimen was brought to the surface. 

T/ie Rough Rook of Observations, Form S. — Books COUtaiuiug fifty leaVeS, 

having these forms printed on each page, were bound in suitable style for 
the pocket, and the navigators used them in all astronomical observing. 
It was the custom of the "Blake's" navigators to take one or more observa- 
tions at each sounding during the day and frequently between soundings 
also, while at twilight, both morning and evening, they continued to get 
them as long as the twilight gave a bright star above a distinct horizon. 
The intention was not, necessarily, to compute all, but to have them avail- 
able should those which were computed fail to give good results. 

With Form 5 is given the label for the cover of the Rough Book of 
Observations. 

The Navigation Forms, Forms 6, 7, 11, and 13. — ThCSe are the OUly formS 

used on board the "Blake" for the computation of astronomical observa- 
tions, and, with the remarks written upon them, they constitute the whole 
navigation record sent to the office, excepting the data contained on the 
General Record Form. 

Form 6 is for computing chronometer errors by Equal Altitudes, for 
recording positions by bearings, and for all computations for which the 
arrangement of Forms 7, 11, and 12 is not adapted. 

Sumner's Method by Moon, Planet, or Star may be worked on Form 



174 DEEP-SEA SOUNDING AND DEEDGING. 

7; Sumner's Method by the Sun on Form 11; and the Meridian Altitude 
of Sun, Moon, Planet or Star on Form 12. 

The occasion was very rare that required the use of Form 6 when 
working on our lines. Forms 7, 11, and 12 were employed almost exclu- 
sively, full advantage being taken of the comprehensive scope of Sumner's 
Method. 

T/te Plotting Form, Form 13 (A and B) . — Thls Is uot indispcnsable, but 
its use systematizes the work of plotting and thereby very much lessens 
the probability of making errors. It was regarded by us as a great con- 
venience, and its use will become apparent when the plotting of the work 
is explained. 

SCHEME OF NAVIGATION RECORD, 

When at work on a line of soundings the navigators arrange the com- 
puted observations in order of time, for convenience of reference. After the 
arrival of the vessel in port, and when the chronometer errors have been 
ascertained, the chronometer rates are worked back for each day on the line. 
Then each observation, beginning with the first of the series, undergoes a 
verification by the assistant navigator, the new chronometer rates being 
introduced. The executive officer, who is also the navigator, beginning 
with the line first run, and keeping each line distinct, selects such observa- 
tions as are deemed worthy of consideration, and, still preserving the order 
of time, numbers them in a regular series by numeral letters as they come 
from the assistant navigator. After a few observations have been verified 
the navigator begins the plotting, and the work of verification and plotting 
go on together, usually keeping pace with each other. 

After the plotting has been completed the accefted observations — those 
not rejected as the plotting advances — are renumbered in a new series by 
order of time, and are designated by the numeral figures. The rough copies 
of the Navigation Forms retain the symbols of the first numbering, and 
receive also those of the second series, but the smooth copies sent to the 
office bear only the numeral figures — that is, the revised numbers. Thus 
we have the selected observations numbered in two series, one series 
embracing all that were selected and considered, and the other series only 
those that were finally accepted in the plotting. 



NAVIGATION AWD EECOEDS. 175 

The utility of numbering in a series all tlie observations to be con- 
sidered is, I think, apparent, and it is probably equally clear that a renum- 
bering or a rearrangement of the accepted observations in a second series 
is necessary in order to restore the continuity of a first series that has been 
broken by the rejection of some of its component parts. Since an obser- 
vation may have a different number in the second series from that which it 
had in the first, to escape confusion a distinct notation or symbolization 
must be adopted for each series ; hence the employment of both numeral 
letters and numeral figures. Throughout the Navigation Record no other 
use is made of the Roman numerals than that already specified. 

Each line of soundings of any season is designated by a letter accord- 
ing to alphabetical order and order of time, and all specimens, soundings, 
stations, observations, positions, &c., on a line are referred to the line letter. 
On the Navigation Forms the various positions established by astronomical 
observations or by bearings of objects on shore are also marked serially in 
order of time, and on the Sounding-Sheet are designated by symbols such 
as Si, S2, S3, &c., for line S. The use of the symbols will be appreciated 
when it is called to mind that upon the Sounding-Sheet may be plotted 
many intersecting lines of soundings, each line exhibiting a number of 
Definite Positions obtained by observation. On board the "Blake" a 
person would be readily understood were he to say that Sounding 13, 
on Line S of 1875-76, was taken at Position 10, or Sw, determined by 
Observations 8, 9, and 10. 

HOW TO KEEP THE PLOTTING FORM; ITS USE. 

In plotting a line of deep-sea soundings, as in plotting an inshore line, 
the line itself is first laid down by fixing and connecting the successive 
positions obtained by observation, after which the soundings are located 
on the line as thus laid down. 

It is very confusing in plotting to be obliged to refer, forward and back, 
repeatedly to the General Record and the many Navigation Forms, on 
which there is avast deal of data of no use in plotting; but with the Plot- 
ting Form this necessity is obviated, for on the latter, by a preliminary 



176 DEEP-SEA SOIJKDING AND DEEDGING. 

operation, all the necessary data, and no more, are arranged and combined 
in such a way as to facilitate subsequent selection and comparison. Form 
13 A shows the Plotting Form fully prepared for beginning the plotting 
of line S, while Form 13 B shows its condition when the plotting has been 
completed. 

All the bearings, angles, and astronomical observations to be considered 
in plotting the work are arranged on the Plqtting Form (Form 13 A) in 
order of time; the observations are numbered in Roman numerals in a 
regular series, and the data for laying down the lines of position, together 
with the courses and distances that have been made to each observation or 
change of the course from the preceding observation or change of the 
course, are correctly placed in their appropriate columns. A change of the 
course, when there is no corresponding observation, is designated by the 
letters C, C in the " ohjecf column, and to secure a proper spacing it should 
be entered as soon as its place has been reached, and not after all the data 
from the various Navigation Forms have been first entered throughout the 
whole Plotting Form. 

The courses and distances are obtained by an inspection of the^cowrse" 
and ''patent-log'' columns of the General Record Form in comparison with 
the patent-log readings on the Navigation Forms. Confusion may arise 
herein if it be not borne in mind that the courses and distances are arranged 
on the General Record in their relation to the soimdings, while on the Plot- 
ting Form they are arranged in their relation to the observations. 

As an example of a case in which a mistake might be made if care were 
not exercised, it will be shown how the courses and distances are entered 
on the Plotting Form between Observations IV and V. 

There are given liereAvith specimens of only seven of the completed Navigation Forms. Their serial 
numbers happening to be the same by both numeral letters and numeral figures, they have been marked on the 
headings with the numeral figures only as being smooth copies. After entering these specimen observations on 
the Plotting Form, the results of others, of which no specimen copies are thought necessary, have also been 
entered in order to complete the record for one da}'. 

Observation IV was taken between Soundings 5 and 6 (shown by the 
back of the Navigation Form, or by a comparison of the reading of the 
patent-log on the General Record with that on the Navigation Form). 
From the time of the observation, when the patent-log read 46.4 miles, the 



NAVIGATION AND KECORDS. 177 

General Record shows that the vessel continued on a S, I E. course until 
Sounding 6, when the patent-log read 50.4 miles — a distance of 4 miles. 
Immediately after Sounding 6 the course was changed to south (see Gen- 
eral Record, Sounding 7, '' course from last sounding''), and remained un- 
changed at Sounding 8, when the patent-log read 70.2 miles — a distance 
of 19.8 miles. 

Observation V was taken at Sounding 8, as the patent-log readings at 
once show, and thus it should be entered on the Plotting Form, between 
the records of Observations IV andV, that the course was changed at 
S*" 25™ a. m. (assumed to have been changed from the time the sinker 
touched bottom at Sounding 6), when the patent-log read 50.4 miles, and 
after the vessel had steered S. I E., 4 miles, since Observation IV; and 
for Observation V it should be recorded that the vessel had steered south, 
19.8 miles, since the change of course mentioned. 

As the plotting of the work progresses and the location of the Definite 
Positions are determined, the method followed in getting each of these posi- 
tions from the observations is stated in the second column of '■'remarks'''' 
on the Plotting Form. It should be borne in mind by the person who plots 
the work that while his memory is charged with many important facts 
concerning the navigation of the vessel, these facts will be altogether out of 
the reach, excepting through the records, of those who may in the future 
revise his work. His aim should be, therefore, to prepare the "remarks''' 
for the benefit of persons who understand plotting, but who are unfamiliar 
with the circumstances attending the work itself. A similar principle 
should be applied to all the records. 

The first column of "courses and distances" on the Plotting Form is 
made to show, at each observation or change of the course, the run from 
the preceding observation or change of the course with reference to all the 
observations which were placed under consideration. The second column 
of "courses and distances" is used to rearrange the traverse data to suit the 
accejpted observations only. Thus, for example. Observations VIII and IX 
(Form 13 B) having been rejected in the plotting, the columns are made to 
show in the simplest form the run to the accepted Observation 8 from the 
accepted Observation 7 (to Observation X from Observation VII) . By the 
23 D s 



178 DEEP-SEA SOUNDING AND DEEDGING. 

first column of ^'courses and distances" the run to Observation X {acce^pted 
Observation 8) from Observation VII {accejpted Observation 7) reads S. by 
E. I E., 10.3 miles, S. t E., 5 miles, and S. i E., 5.3 miles, while in the 
second column it is stated compactly as S. by E. I E., 10.3 miles, and S. t 
E., 10.3 miles. 

When the plotting has been completed, the ''remark'' column filled 
out, the second numbers given to the observations, and the latitude, longi- 
tude, and serial number of each Definite Position recorded, we have on the 
Plotting Form, exclusive of the computations of observations, all the infor- 
mation needed to effect a replotting of the Definite Positions on the line 
of soundings by either series of observations. 

There should be transcribed from the Plotting Form to the rough 
Navigation Forms all the explanatory remarks from the second column of 
"■remarks'' ; also, the latitudes, longitudes, and serial numbers of the Definite 
Positions. I will again state that the rough Navigation Forms, both on the 
headings and in the remarks, should give the observation numbers in both 
series; but the smooth copies, for transmission to the office, should give 
only the numbers in the second series. The forms of those observations 
which are thrown out in the plotting are marked "■Rejected," in large letters 
across the face, with red or blue pencil, and may be filed away in the 
Archives with the rough forms of the accepted observations or by them- 
selves. We never sent the Plotting Form nor the Plotting-Tracihg to the 
office because, the ''Blake's" work being continuous, the party on board 
could always be called on by the office for a replotting; but with a brief 
explanation on the Plotting Form, to show the use of the first and second 
arrangement of numbers, courses, and distances, that Form and the Tracing 
might form very useful additions to the office records. 

THE ARCHIVES. 

The establishment of the Archives was by no means a caprice; on the 
contrary, it was a legitimate consequence of the many embarrassing circum- 
stances which suggested it; and it can be stated with confidence that, by 
taking a great number of observations, by recording them with full infor- 
mation in the systematically arranged Rough Book of Observations, and 



NAVIGATION AND EECOEDS. 179 

by preserving all of them for future reference, many miles on lines of 
soundings were saved which otherwise would have been lost. 

THE PLOTTING-TRACING AND THE SOUNDING-SHEET. 

It grew to be our custom to plot, not directly on the Sounding-Sheet, 
but on a piece of tracing-paper laid over it and upon which were traced the 
parallels, meridians, compasses, and graduated scales required to plot the 
line of soundings in hand (Fig. I, Plate 35). By pricking through the 
Tracing positions could afterwards be transferred readily to the Sounding- 
Sheet. The finished Sounding-Sheet (Fig. 2, Plate 35) contained on each 
line the Definite Positions, the points where the course was changed, the 
soundings, the character of the bottom-soil specimens, occasional surface 
currents by dead-reckoning or by actual observation with floats, and the 
direction of the wind at frequent intervals. 

When the transfer had been made the Tracing was cleared of all 
superfluous pencil-marks, and filed away in the Archives on board the 
vessel, where it remained from year to year for reference. 

In case lines of soundings subsequently run did not intersect consist- 
ently with lines already plotted, the Plotting-Tracing was taken from the 
Archives and the plotting work subjected to a careful revision. This Trac- 
ing, besides greatly facilitating revision, saved the Sounding-Sheets from 
much of the wear that would have defaced them during the successive 
seasons that they were used on board the vessel. 

Although the Sounding-Sheets were sent to the office at the end of 
each season, they were usually returned, after being copied, to serve for 
further work in the same locality. 

Fig. 1, Plate 35, shows the Plotting-Tracing of Line S cleared of 
superfluous pencil-marks and ready for the Archives. 

DETAILS OF THE PLOTTING OF LINE S. 

Estahusuina the Positions (Fig. 1, Plate 35). — By reference to the Plot- 
ting Form it is seen that the ''departure'' on line S was taken from South 
Pass and Pass a TOutre Lights at S*' 40" p. m. on May 9. A plotting of the 
bearings gives the first Definite Position, which is designated by a circle of 



180 DEEP-SEA SOUNDING AND DEEDGING. 

one-eighth-inch radius, and marked Si. At 9^37"" p.m. bearings were again 
taken of the same lights, by which we get Position S2. 

The course and distance by dead-reckoning from Position Si to the 
time of Position S2 — S. t E., 5.1 miles — is represented by a dotted line. 
It is well to draw the line of course and distance after the manner shown — 
^. e., from a Definite Position — when this can be done without producing a 
confusion of lines on the Tracing, but it may be laid off as shown from Posi- 
tion S7, or from any part of a line of position, instead of from a Definite 
Position on that line. The requirement is simply to make it clear between 
which Definite Positions, or lines of positions, the run by dead-reckoning 
was made. If drawn on one side, the parallel rule and the dividers will 
carry it up to any place where it may be needed. 

With a line of soundings of no very great length it is a good plan to 
lay down all the Sumner and other lines of position, and to mark each with 
its appropriate legend before plotting positions other than those obtained 
by bearings of objects on shore. We generally drew lines of position and 
Definite Position circles and symbols in red ink. 

From Observation I to Observation II the vessel made 1.1 knots, S. 
\ E., by dead-reckoning. To find the Definite Position on Observation II, 
lay off the run from any part of Observation I, and frorn the lower extrem- 
ity of the line thus projected draw another line parallel to Observation I, 
which will intersect Observation II in the position sought — that is, Posi- 
tion S4. 



When referring to the plotting the term " observation " will, for brevity and convenience, often be used 
instead of " line of position " or " Sumner -line." 

From Position S^ lay back the run made, by dead-reckoning, between 
Observation I and Observation II; the line representing the run will cut 
Observation I in Position S3; or carry back Observation II, by course and 
distance, to an intersection with Observation I. In getting Position S3 and 
Position S4 no current nor drift was allowed for in the run. A line drawn 
from the point A — the dead-reckoning position at the time of Observation 
I — to Position S3, would represent the current or drift from the time the 
vessel was at Position S2 to the time of Observation I — S. E. I E., 2.4 
miles in the elapsed time of ^^ 4"", a velocity per hour of 0.8 mile. From 



NAVIGATION AND RECORDS. 181 

this it seems plain that the Positions S3 and S^ need not be revised to 
allow for current, since Observation II was taken only six minutes after 
Observation I. 

It is seldom tliat any deafl-reckoiiing current need be allowed in suoli short runs between observations. 
What from custom is here styled cm-rent, is evidently sometimes ver^' different from the true current, and results 
from current, headwaj-, and sternboard during soundings, imiierfect steerage; and leeway, if it has not been 
allowed for in correcting the courses. During the operation of sounding a vessel is so constantly n 



to keep the wire vertical that no accurate run can be kept of her drift over the ground on such occasions. Since 
the stoppages vai-y in time — because the soundings vary in depth, and from other circumstances — the dead-reck- 
oning current between two widely-separated positions — as Si and S3 — does not, by any means, always give a 
measure of the drift at each intermediate point; hence it would be of no avail in jjlotting to strive tor a <legree 
of exactness unattainable from the nature of the work. I have no intention to encourage laxity ; on the con- 
trary, I would insist on accuracy wherever it is possible; but it is useless to accord to results involving speculation 
more than their merited value. 

As each Definite Position is determined, explain in the second ''remark''' 
column of the Plotting Form the method adopted in its determination; 
and if any allowance for current has been made, the fact should be stated, 
mentioning if the current was by dead-reckoning or by observation with 
floats. The wind and current between positions are indicated by arrows, 
as shown on the plate. The velocity per hour of the current, in knots 
and tenths, is designated by figures, and the force of the wind is expressed 
by the figures of the usual weather notation. The arrows, on the whole, 
present a very good general indication of the- direction of the currents. 
By reference to those plotted in previous years we were enabled, in 1878, 
to run a series of lines of soundings in various directions in the Straits 
of Florida and the Yucatan Channel, across the swiftest currents of the 
Gulf of Mexico, with such precision as to elicit the special commendation 
of the Superintendent of the Coast and Geodetic Survey. 

Positions S5 and Sg are obtained from Observations III and IV after 
the manner of getting Positions S3 and S^ from Observations I and II — i. e., 
by carrying Observation III forward, by course and distance, to an inter- 
section with Observation IV, and Observation IV back to an intersection 
with Observation III. 

From Observation V, which gives a Sumner-line of position by the 
forenoon sun, we could get at once a position close enough for ordinary 
navigation by referring it to the Definite Positions S5 and Sg; but for our 
purpose it is necessary to take into consideration, likewise, the noon and 



182 DEEP-SEA SOUNDING AND DEEDGING. 

afternoon observations, Nos. VI and VII, the first step being to determine 
the Definite Position on the noon parallel, Observation VI, 

The forenoon observation, No. V, carried forward to an intersection 
with the noon parallel, Observation VI — which is done by simply prolong- 
ing the Sumner-line, because the course is directly along that line — gives a 
position at B, while the afternoon observation, No.~VII, carried back gives 
another position at G. To determine Definite Position Ss, it is assumed 
that from the time of Observation V until the time of Observation VII the 
current remained unchanged in direction and velocity, and that the ves- 
sel's drift in a true westerly direction is represented by the distance from 
B to C, without regard to any possible northing or southing. 

It is evident that this assumption is not strictly true, for had simultaneous observations of two objects on 
different bearings been taken at the time of getting Observation V, their lines of position would not have worked 
to an intersection with Observation VI at exactly the same point on the parallel. To avoid misunderstanding, 
we usually called the distance from B to C discrepancy ; but we treated it as true drift, unless there were reasons 
to the contrary. 

If, therefore, from Q^ 15"" a. m. until 2'' 58™ p. m., an interval of S*" 37"" 
(remembering that the clock was set ahead 6™ at noon), the drift was 1.7 
miles — as represented by the distance from B to C — from G'' 15" a. m. until 
noon, an interval of 2*" 39" (clock set ahead 6"), it was 0.8 mile. The 
distance 0.8 mile laid off on the noon parallel from B toward G gives 
Position Sg. This is the method usually followed in getting the position 
on a noon parallel by means of one forenoon and one afternoon observa- 
tion ; but should there be doubts of its correctness in certain instances, 
the dead-reckoning currents found by working forward or back to noon 
from the morning or evening twilight positions will probably point out if 
the method be admissible. With several forenoon and several afternoon 
observations worked to noon there can be no great uncertainty of getting 
a trustworthy position, provided all the observations are good. 

Having determined the noon position we are prepared for a return to 
the Definite Position on Observation V. Observation V makes so small an 
angle with the meridian that it will give a close approximation to the cor- 
rect longitude for any latitude likely to be assumed; hence it is- with the 
determination of the latitude that we need most concern ourselves. The 
course and distance carried forward from the Dejinite Position So gives a 



NAVIGATION AND EECOEDS. 183 

dead-reckoning latitude at D, and by working back in the same way from 
the Dejinife Fosition Sgwe get another dead-reckoning latitude at E. In- 
terpolating for time-intervals we get a mean latitude between the points D 
and E, which, laid off on Observation V, gives Position S^. 



It is interesting to 


note that wl; 


len carried 


to intersection with Observation V, Observatioi 


:r III gi. 


position at F, Obsei-vatioi 


1 IV at G, a. 


ul Observi 


ition VI at H, and that a mean of these positio: 


.IS diifers 


little from Position S7 aire; 


ady found'. 









The true position of the vessel when the course was changed at S*" 25" 
a. m. — after she had steered S. I E., 4 miles, from Position Sg — should 
next be sought. If in ^ 40°\ the time from Position Sg to Position S7, she 
drifted E. N. E. I E., 1.2 miles, as represented by a line drawn from D to 
Position S7, in 50"" (the time from Position Sg to the changing of the 
course), she must have drifted E. N. E. i E., about 0.2 mile, assuming the 
drift to have been invariable from Position Sr to Position S^. The true 
position is therefore marked at a point 0.2 mile E. N. E. i E. from the 
dead-reckoning position, and designated by a circle of iV-inch radius. 

For finding the correction to be applied to the dead-reckoning position of the vessel at changes of the 
course, in order to locate the true position, it might prove convenient, in extended plotting, to make use of a 
diagram similar to that shown in the right upper corner of Fig. 1, Plate S5. One of these could be constructed 
in some vacant corner on each Sounding-Sheet, and by having the scale of miles on the diagram the same as that 
of the projection the correction, as taken from the former with a pair of dividers, could be applied directly to the 
dead-reckoning position. Any expansion or contraction of the paper from time to time would probably equalljfc 
affect the diagram and the projection. 

Example : If in 8'> 45"' the drift was 2.5 miles, how much was it in 2'" 40™ ? The dotted line a h on the 
diagTam represents the drift sought, which by computation is 1.04 miles. 

Before seeking a Definite Position on Observation VII, Position Si 
should be determined. Observations X and XII were taken only 20™ apart, 
during which interval the vessel was engaged in sounding and manoeuvring. 
From this it appears that we can do no better than to locate Position Sio at 
the intersection of Observations X, XI, and XII. 

The Sumner-lines corresponding to Observations VIII and IX, which 
were originally accepted, have been purposely shifted 4' in longitude to 
the eastward, that they may be found unfit for acceptance, and so give 
an opportunity to show in what manner rejected observations are treated 
in the record, or, perhaps more strictly, how the records are amended for 
rejected observations. 

Position Sg on Observation VII is obtained by running the course 



184 DEEP-SEA SOUNDING AND DEEDGING. 

and distance forward from Definite Position Sg and back from Definite 
Position Sio for a dead-reckoning latitude, after the manner of proceeding 
in the case of Position S?. 

If, instead of getting Position Sg by the method just stated, the noon observation and the evening twilight 
observations were to be carried to intersections with Observations VII, the several points of intersection would 
be as follows : By Observations VI at J, and by Observations X, XI, and XII at K, L, and M, respectively. 
The lines of position of Observations X and XI, making only the small angle of 18*^ with the line of position of 
Observation VII, give untrustworthy results, but that of Observation XII, making an angle of 42°, would give a 
a tolerably good position if coupled with Observation VI. 

It is well to take plenty of time for consideration when plotting, and 
to make a practice of running courses and distances forward and back, and 
of carrying the lines of position to intersections by various combinations, 
as a means of detecting those observations which, through one cause or 
another, are least worthy of acceptance. 

The position where the course was changed between Sg and S^o should 
now be found, the successive positions connected by right lines, and the 
winds and currents along the whole line of soundings ascertained and 
designated by arrows. Then the Plotting Form should be completed in 
every particular; after which it may be laid aside and the General Record 
Form taken up for the purpose of plotting the soundings. Unless the 
independent points where courses were changed are known, it would not 
be possible to plot the soundings correctly. While these points are deter- 
mined and specially marked to serve a necessary purpose, they are not 
classed with the Definite Positions, so called, because they do not occur 
on any astronomical line of position nor on any line of bearing of a shore 
object. It might be convenient to call them Secondary Positions. 

DETAILS OF THE PLOTTING OF LINE S (CONTINUED). 

Plotting the sotinaings.— AW the souudlugs takcu betwceu any two suc- 
cessive Definite Positions are generally plotted on a right line connecting 
those positions, but if an unusually prolonged delay has been made at any 
cast, making it evident that an exceptional allowance for drift or current 
should be applied in that instance, then it may not be practicable to adhere 
to the right-line method, and the case becomes one of special judgment, 
dependent on circumstances. When such cases arise, it should be remem- 
bered that, the method by right lines being the one usually followed, all 



NAVIGATION AND EECOEDS. 185 

deviations therefrom should be specially mentioned in the column of 
''remarks'' on the Plotting Form, to be transcribed to the proper Naviga- 
tion Forms. It is desirable that the navigation record should not be 
encumbered by such supplementary remarks, and they may often be 
avoided by taking observations at short intervals along the line of sound- 
ings, especially at different times during the long stoppages. When work- 
ing over gentle slopes like the Great Florida Bank, where for more than 
one hundred miles seaward the water is of less depth than one hundred 
fathoms, greater exactness is called for than is absolutely required in the 
deep basin beyond, as it is probable that navigators at large will turn to 
good account the soundings shown on their charts within the curve of one 
hundred fathoms. Line S, part of which has just been plotted, crossed 
very strong currents as we approached the Yucatan Bank, and on line T, 
run soon after from Alacran Reef to Tortugas, we experienced on leaving 
the Bank such a strong head wind and heavy sea, and such a swift current 
setting up through the Yucatan Channel, that the dead-reckoning current 
was five miles per hour at right angles to the direction of the line of 
soundings. On each of these lines we had, as a result of our astronomical 
observations (thirty-eight observations on Line S and sixty on Line T), as 
many Definite Positions as there were soundings, although the position by 
observation was not always that of a sounding. The right-line method 
was followed in plotting, but with so many Definite Positions the location 
of the soundings on our Sheets cannot be much in error, notwithstanding 
the rapid drifting of the vessel. 

Fig. 3, Plate 35, illustrates the plotting of the soundings between 
Positions S2 and S3. Sounding 2 (one hundred and twenty -seven 
fathoms) was taken after a run, by patent-log, of 4.9 miles from Position 
S2, and Sounding 3 (three hundred and eighty-six fathoms) after a run of 
10.3 miles from Sounding 2, or of 15.2 miles from Position S2. In the 
present case these intervals might be laid off on the dotted line repre- 
senting the run from S2 to S3, and thence might be carried to the line 
proper, but frequently the line of the course and the line of soundings 
coincide so nearly in direction that other means must be adopted, and the 
manner of working may be as follows : Draw at any convenient angle with 



186 DEEP-3EA SOUFDING AND DEEDGmG. 

the line of soundings a right Hne S2 P, equal to the distance by patent-log 
from Position S2 to Position S3 — equal to S2 A, or 16.2 miles. Lay off on 
the right line S2 P the sounding -intervals S2 N (4.9 miles), and N 
(10. 3 miles), as given by the patent-log readings on the General Record 
Form. From the points N and draw parallels to the right line S3 P, 
intersecting the right line connecting the Positions S2 and S3. The points 
of intersection are the positions to be assigned to the respective soundings. 
The right line S2 P may be drawn at discretion, but the method of obtain- 
ing the most convenient angle possible is shown by Fig. 3. From Position 
S2 as a center, with a radius equal to S2 A, describe the arc of a circle 
as shown. From Position S3 draw a tangent, to the circle. The right line 
S2 P, touching the circle at the point of contact with the tangent, gives 
the best angle that can be obtained. 

There are other ways of plotting the soundings on right lines joining 
positions, but they need not be explained here. 

When a change of the course is marked between two Definite Posi- 
tions, the soundings are plotted from the first position to the change of 
the course, and then from the latter to the second position. 

REMARKS AND SUGGESTIONS ON PLOTTING AND NAVIGATION. 

If the sun pass the meridian near the zenith, equal altitudes of that 
body give a quick and trustworthy means of finding the longitude for 
noon; but the conditions which are favorable for that method also greatly 
increase the value of the Sumner-line of position for the same purpose. 
Although the advantage of easy computation is on the side of the equal 
altitudes, it is more than probable that on the arrival of the time which 
would be selected to take the ante-meridian observations of the set there 
will have been already computed, for positions intermediate between twi- 
light and noon, two or more Sumner-lines, which, with scarcely any addi- 
tional labor, may be carried forward to be considered in connection with 
the afternoon Sumner-lines for finding the noon longitude. When we 
observed equal altitudes on board the "Blake" it was chiefly for securing 
a check, or for providing a substitute in case of the loss of the usual fore- 



NAVIGATION AND EECORDS. 187 

noon observations, or to insure a noon longitude against the failure of the 
afternoon Sumners. 

The cases shown on Fig. 1, Plate 35, of getting the daylight positions— 
S;, S„ and Sg— are of a simple character. Were it advisable in this chap- 
ter to discuss the management of Sumner-lines in general, a different line of 
soundings would be chosen for illustration — one that would involve some 
perplexities in the plotting work. The mode of finding the Definite Positions 
on the forenoon and afternoon Sumner-lines changes with the conditions, 
even when the data is complete. Thus in the cases already plotted the lati- 
tude at the time of observation was most in doubt, but had the latitude of 
the vessel and the declination of the sun been widely different it might have 
been that the longitude was' least well defined by the Sumner-lines in point, 
and this would probably have caused us to arrive at the Definite Positions 
by other steps. It sometimes happens, when the same course has been 
held between a twilight and a noon position, that a right line connecting 
these two positions will intersect the forenoon or afternoon Sumner-lines in 
the most rational points for the position of the vessel on those Sumner-lines 
at the respective times of observation. This is the easiest of all cases for 
solution. When there has been hazy or cloudy weather the difficulty in 
the plotting work which follows is greatly increased. . On one occasion 
three days were spent by me in determining a single Definite Position on a 
line of soundings that had been run in a heavy sea with a dim horizon. 
This was troublesome, but in the end there was satisfaction in feeling that 
my conclusions were sound. The troubles are not confined to the fore- 
noon and afternoon positions only, but may arise anywhere. On occasions 
there are no forenoon or no afternoon observations, or perhaps both sets 
are missing; at other times the meridian altitude has failed, or morning, 
evening, or all twilight observations likewise; and, again, some observa- 
tions are presumably much more trustworthy than others, calling for care- 
ful comparison and discrimination in plotting. The way out of difficulties 
in plotting, as I have stated before, is to seek for current or drift, or dis- 
crepancy, by working runs forward and backward, by one disposition or 
another, until the errors of observation become apparent. 

There are a number of methods of taking a departure on a line of sound- 



188 DEEP-SEA SOUNDING AND DEEDGING. 

ings. The best, doubtless, is that of measuring with sextants, from the ves- 
sel, the angular distance between three established objects on shore. Two 
objects in range with their angle at the vessel from a third object gives a 
fine position. A good way — for want of a better — is to begin the line of 
soundings at the outer bar-buoy or sea-buoy if leaving a harbor or road- 
stead. Cross compass-bearings on two land objects are almost always 
Avorthy of acceptance when the vessel is quiet; but with us, when they were 
taken in a rough sea or heavy swell, we could seldom get good results from 
them — /. e., when the bearings were projected on a chart the hydrography 
of which had been executed by the most approved methods of inshore 
work, they would not always intersect in the depth found by an actual 
sounding taken at the time of observation. Such a dilemma may possi- 
bly be escaped by getting a compass-bearing of one of the objects and a 
sextant angle between the two. When this does not succeed, and there 
is at hand a trustworthy chart of the place, showing the slope of the bottom 
to be regular and tolerably steep, a compass-bearing of only one shore 
object — several times repeated to make sure — may be projected on the chart 
and the position of the vessel marked where the line of bearing cuts a depth 
corresponding to the sounding taken at the time of observation. When 
admissible, the most suitable line of bearing on which to place the vessel 
for this purpose would, doubtless, be one taking a direction normal to the 
curves of equal depths. Sometimes we were compelled to take a departure 
from an isolated light-house, or other object, where the circumstances 
were such that to accept a position by one bearing and a sounding was 
out of the question. In such cases we generally managed to approach the 
object so as to get the possible advantage of what is known as the bow and 
beam-bearing problem. With the vessel steadied on her course, a bearing 
was taken of the landmark when it bore four points on the bow and 
another when it was abeam, holding the same course between, and reading 
the patent-log at each bearing. When there was no current the distance 
from the landmark at the second bearing was equal to the distance run 
between the two bearings. If the existence of current was suspected, then, 
at the second bearing, an observation was made by means of floats from a 
boat anchored to the sounding-rope. Any current thus found was applied 



NAVIGATION xiND EECORDS. 189 

to the run, and if it proved to have been at an angle with the course steered 
the character of the problem was changed, and the case was solved by- 
projection on the Sounding-Sheet in accordance with the data. A check 
on the above is to leave a buoy at the spot where the second bearing w^as 
taken, and then, continuing the same course, to get a third bearing and a 
patent-log reading when the object bears four points on the quarter. By 
returning to the buoy a departure may be taken at pleasure. 

Methods that are adapted to taking a departure on a line of sound- 
ings are alike suited to closing the inshore end of a line. 

Changing the course between observations should be avoided as much 
as possible when on the lines, that the plotting work may not be complicated. 
Very often at evening twilight it is known that no more observations will 
be obtained until morning twilight, and that a course must be shaped for 
all night. We learned, after a few severe disappointments in the strong 
surface flow of some parts of the Gulf of Mexico, to shape the course for 
the night directly along the projected line of soundings, unless quite sure 
that W' e could predict the general direction and approximate velocity of the 
current. It was very unpleasant to find by the morning twilight position 
that the course had helped the current to carry the vessel aw^ay from her 
line. AVhile five miles of deflection might not give great concern, ten 
miles in the same case might be thought to detract very seriously from 
the appearance or the adequacy of the work. 

For positions we placed our dependence chiefly on the twilight obser- 
vations, as giving us, practically, the latitude and the longitude at the same 
time. A twilight horizon is, in general, a very fine one, the bright sky 
beyond throwing, it out black and distinct, thus offering the best of condi- 
tions for accurate contact in measuring altitudes at sea. To get fine inter- 
sections like that given by Observations X, XI, and XII (Fig. 1, Plate 35), 
was by no means an unusual occurrence with our navigators. 

By always knowing in advance the names, approximate bearings, and 
altitudes of the stars that each wished to observe, our navigators never lost 
opportunities when the time for observing had arrived. Since with Sum- 
ner's Method the line of position is always at right angles to the line of 
true bearing of the body observed, the angles which the several lines of 



190 DEEP-SEA SOUNDING AND DEEDGING. 

position would make with each other could be foretold at once from the 
compass-bearings of the objects at the time of observation; hence, in select- 
ing the planets or stars for our purpose a due regard was had to their rela- 
tive bearings. Eight points evidently gives the perfect intersection, while 
one of two points is hardly acceptable for good work. When there was so 
little clear sky at twilight that the constellations were indistinguishable, the 
altitude of the first bright star that presented itself favorably was turned 
to account, for with the altitude, and the bearing that we habitually took 
simultaneously therewith, a reference to our handy little celestial globe 
rarely failed to give us the name of the star. While a globe was not 
exactly a necessity, hardly a day passed at sea that it was not put to 
good use for instruction or amusement. We did not often attach para- 
mount importance to meridian altitudes of stars at twilight, for, in the time 
given up to watching for the culmination, opportunities for fine altitudes 
for Sumner-lines might have escaped notice, and the advantage of observ- 
ing at the very best phase of the twilight horizon might have been lost to 
us. The records of the "Blake" show nevertheless that a large number 
of meridian altitudes of stars were taken during the period covering the 
whole work, thereby proving that we were not neglectful of them when 
they served our purpose best. 

Whenever an observation is needed and can be secured, the navigators 
should be cautious about deferring it in anticipation of a better chance, for 
the prospective chance may come to nothing, and they will then have only 
regrets instead of "salted" observations, as we called those taken for pre- 
caution. Occasionally, good altitudes of stars or planets may be had on 
moonlight nights — at times when the moon is not too high — by observing 
such bodies as will come to a contact just at the limit of the illuminated 
portion of the horizon. Such opportunities should not be neglected, 
especially when by embracing them any good purpose may be served, 
because it is often the case that a sky which has been clear all night 
becomes temporarily overcast toward the break of day. Our old hands 
were always alive to these points, and the new-comer quickly worked his 
own cure, for he was sure to find that diligence in observing lessened the 
perplexities of plotting. 



NAVIGATION AND EECOEDS. 191 

AVlien the navigators were' in danger of being overworked, we found 
it a good plan on moonlight nights to leave with the officer of the deck a 
memorandum showing the watch-time of the meridian-passage of the moon 
or of some of the stars or planets. If the officer of the deck succeeded 
during the night in getting any meridian or other altitudes they were com- 
puted by the navigators on the day following. 

If the weather became overcast or foggy at a time when further prog- 
ress on the line of soundings without observations was thought to be a 
serious disadvantage, we would, when working in water less than two 
hundred fathoms in depth, plant a buoy, or anchor the vessel, and await 
clearing weather. By anchoring at intervals, we once executed success- 
fully a line of considerable length, the whole of which would otherwise 
have been lost. 

SECTIONS AND TEMPERATURE CURVES. 

Forms 14 and 15 are given as specimens of what may probably be 
considered the most important graphic methods of arranging for study the 
data obtained at the observations for serial temperatures, while Form 15 
serves at the same time for presenting in a simple and comprehensive 
manner other useful information. 

Our instructions did not require us to submit anything of this kind to 
the office, but after our first season in .the Gulf of Mexico we began to add 
Form 15 to our records, and in time a continuance of the practice was 
expected of us. Form 14 never formed part of our records; it is chiefly 
because of its special importance to a party when actually engaged in the 
work that it is given here. 

Form 14.— With a plece of cross-section paper at hand, the curve may 
be constructed from the data in a few minutes. The horizontal or upper 
scale represents degrees of temperature, and the vertical or side scale 
fathoms of depth. The point corresponding to any depth of a series is 
plotted at the intersection of the vertical and the horizontal lines repre- 
senting, respectively, the temperature and the depth. The successive 
points are then connected by right lines, or all the points may be embraced 
in a consistent curve. 

This Form may be made to exhibit the relation between depth and 



192 DEEP-SEA SOUNDING AND DEEDGING. 

temperature for a single station or for a number of stations. In the lat- 
ter case, the results obtained at the several stations may be compared. 
The gradients of a curve, by showing the rate of change in temperature 
between successive points of observation, give evidence of the existence 
of currents; but if any gradient show an abrupt divergence from the 
general aspect of the curve it may be found that this results from an 
instrumental error, and thus a curve will point out the necessity for a 
repetition of an observation. 

The heavy vertical line represents the temperature of 392° Fahr., 
the lowest temperature of the deep waters of the Gulf of Mexico, and 
that which we always found there below a depth of six or seven hundred 
fathoms. 

Form 15, — It is usual to make sections of this kind on profile paper, 
which gives a clear exhibit of the lines, but cross-section paper being 
more convenient in our special case was always used by us. The scales are 
arbitrary, that at the top representing miles and that at the side fathoms. 
The depth is generally so small in proportion to the distance run that it is 
necessary to greatly exaggerate the former in order to present the data-in 
a shape available for inspection. 

The data was plotted on Form 15 as follows : From the position of 
.each sounding on the Sounding-Sheet (Fig. 2, Plate 35) a perpendicular 
was drawn to a right line connecting the positions of the first and the last 
sounding on the Sheet. The several distances of the new or projected 
positions from the first sounding of the series were then set off on the 
scale of miles on Form 15, and, from the corresponding elements of depth 
and distance, the curve or profile of the bottom was constructed as shown. 
The further construction of the lines shown on the Form is so apparent as 
hardly to need special description. In drawing the lines of equal tempera- 
ture it was our practice to first join such points on adjacent lines of descent 
as were shown, by actual observation, to have equal temperatures. The 
figures on the line representing the surface of the water denote temperature 
of the surface water. 



ABBREVIATIOXS OF BOTTOMS. 

'or Mud. bk. for black. Iird. fur hard. 



WEATHER SYMBOLS. 



)4' 35". 
UNG. 

, 1876. 



SYMBOLS FOB STATE OF SEA. 



SYMBOLS FOR APPEARANCES OF CLOUDS. 

Cir , Cirrui, Frinum/furm 

Oir Cum Cirro Ounmlui Secondur;) for 
Vir Str, CtnoStrUu^ 

Cum , Oumulus Primury furn 

Cum Sir. Ou) lull *( dti^ Secomhmj fu, 



occupied 



■ounding. 



•mpass course I 
rom last sound- j 



South -. 
South _. 



. South 
. South 



S.byE.iE.. 
S.iE 



3. by E. i E-. 
- S. IE 



DISTAJfCES. 



Initials 

of officer 
of the 
deck. 



\V. 0. S. 
W. 0. S. 
W. 0. S. 



W.E.S 
W. 0. S 



■nnnected with 
affecting the 



Set watch ahead O" at nc 



STATISTICS OF THE LINE. 



Form 3. 

U. H. COAST S UR VEY. 

Off-Shore Soundings, Gulf of Mexico. 

GENERAL RECORD. 

LINE S, FBOM near South Pass, Mississippi River. TO..... latitude 26° 58' 25", longitude 

IN STEAMER "Blake," Lieutenant-Commander C. D. Sigsbee, U. S. N.. Assistant C. S., COMM. 

: BEG UN AT H HO URs 40 MINs. p.m., LATE May 9th, 1876. ENLEL A T 7 NO /,7,'s i'4 uMINs. p. m., LA TE May 



89° 04' 35". 
'AN LING. 
10th, 1876. 



IS FOB APPEiKASQES 01 























































































DATE. 


nil \nl \ 1,1 \( 


Jir ttmpera- 


'""T;rs)."-" 


(ra<«- &„«■(;„. 


turrenU olm zed will jloaU, 


Iia,anet<^ 


Tr/JVD 


Slate of the 
umlhe by 
BynhoU 


i 


Stale of 
\llie«at 


Jvcof 


i3- 




COURSES. 




^f 






inn tolUm. 


l"''t 


Jath- 


'''Bz:- 


'''■::!::: :LnL:::::' 




_ 


..... \ 


-- 


# 


Tu. '•"' 


S 


"i"»f 


■' 


^ 


.... 


.., 


J?o™, of 
b/symlob. 


^r:/ 






■"?■ 


'"!,'"'■ 






"""■ 





'li 




' 


I.mgiludc. 


n 








,y,ntoh 


" 


.. 


" 


. 


Maj9 

M»y 9- 


1„ 


02 


: ;; 


u 


!«(. 


Clmngert the 


W Ul 40 


m 02 35 





-0 


Surface. 


j[ 




i;E 


ji 






— 


,0, 


" 


.V 


' 




cu. ......... 




.. 




« 


« 


., 






aiK 


:: 


r 


w.o.s. 


"-::.x:-;.:,;;v-;, .-.>•..- 




:: : :: 


III 


:;:::::: 


:; 


ii 

Surfaco. 


1 
3»'j 

is 

681 


;;;;;;;; 


J;S 


S 








::: 


™ 










; 


^- 


' 


:: 


J 


10 


j 






: 




..,,,,,,,.,,..,.,„,„ 
















C„„, ......... 








M»J- >0- 




















Mb.v 10 


----- 


1.0.0 


,2 








:■:■::::::::: 


n 


Cir.Cim 
























May 10. ...._ 
















-[*'"'" 




"■'^ '»- - 


''"I'^^^'harolV 
















' 


™ 










;----- 


1.02CZ 


:: 








s. 
















iV" 




May 10 
















C„„ .......... 


1 




May 10 




1.02C8 


:: 








































' 


^_ 


^ 


" 


_'___ 


P 





- 








_^ 


^ 




__^ 
















T^i 


JL 


" 


^ 


a 


» 1 







" " • 


T 







I 



numhrr of 



nd of 



hoitoin 
fathon 



proh,ibh 
ill lays ; 



REMARKS. 

iccidijifs, losses, failures of gear or 
•lis to work satisfactorily, giving 
" ninsi's; give reason for unusual 
mention, generally, matters of im- 
K or ivteres't conmr'tcd with the work. 



648 
676 



hud not been adjusted. 



1077 
1195 
1313 



Form 4. 

• V. S. COAST SURVEY. 

Off-Shore Soundings, Gulf of Mexico, 

SUPPLEMENTARY RECORD. 
LINE S, FROM near South Pass, Mississippi River. TO... latitude 26° 58' 25", longitude 89° 04' 35". 

TW KTEAMEn "B'ok-"L-U + — tC— ^- ^ D S-""He U ^ ^^ iS-'-'a"* C S r,r,.r.,r ., .r-,.j^rr, 

BLGV^ LI 8II0URs40 l/7Ab [ r BAIL Ma> 9tl 18/6 IMJllJ U I[0URs24: ¥/> i I 111 \\ 1 II IS C 



«3 U 



(25 D s) 



194 



DEEP-SEA SOUNDING AND DEEDGING. 



FORM -' 



Oompass-bearing 

Ship's head 

Patent-log 

Obs'n at sounding No. 
Obs'n shortly before sound'g 
Obs'n shortly after sound's ^ 
a between sound'gs Nos. 
Index correction 

REMARKS. 



H. M. S. Ths. ' 



Object... 
Horizon _ 



CARLILE P. PATTERSON, Superintendent. 



Section , 



OBSERVATIONS. 



GENERAL LOCALITY : 



Bough Boole of Observations No. 

From , 18 , Line 

To , 18 , Line 

Vessel., _-.. 

Chief Com' da Hyd. Party: 



195 



FORM (>. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

(Bearings of objects on shore.) 

Line from Lat. "29° 01' 40", Long. 89^ 02' 35". rn Lat. 26° 58' 25", Long. 89° 04' 35 . 
Coast Survey Str. "Blake," Lieutenant -Commander C. D. Sigsbee, XT. S. N., Co.MttANDi.vG. 
Date. May 9th, 1876, j; f^ ^o. of Positjon. 1 & 2. No. of Observation. Bearings. Line Letter. S. 



At Sb 40"' P. M., May 9th, touk our departure on Line S. 

South Pass Light, Missi.ssippi Kiver, bearing (correct magnetic), W. S.W. i W. 

Pass a rOutre " " '■ - ■■ '• N. | W. 

Patent-log, : Sonnding No. 1. 

DEFINITE POSITION BY ABOVE BEARINGS : 

Latitude. 29° 01' 40". Longitude. 89° 02' 35". 

Position 1. 



U 9'' 37" P. M., May 9th, took following bearings: 

South Pass Light, Mississippi Elver (correct magnetic), N.W. by W. i \V. 

Passal'Outre " '■ '• " " N. i W. 

'atent-log, 5.1; Between soundings Nos. 1 and 2. 

DEFINITE POSITION BY ABOVE BEARINGS : 

Latitude. 28° 56' 20". Longitude, 89° 0»' 15". 

Position 2. 



iy6 



DEEP-SEA SOUNDING AND DEEDGING. 

EEMABE8—{ Continued ). 



OBSERVER.^ 
COMPUTER.. 



.Lieut. J. E. Pillsbury, U. S. N. 







TIMES. 


ALTITUDES. CHRO. COMP. REMARKS. 




c. 
■ w. 
c—w. 
a a 

\ a 
1 w. 

G—W. 

1 a a 













197 



FORM 7. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

SVMXEMfS METHOD BY .llOOX. PI.AXET (■ ), STAR (Altair). 

Lt.ve from Lat. -29° 01' 40". Loxg. 89° 02' 35". to Lat. 26° 58' 25". Losg. 89° 04' 35". 
Coast Subtey Sth. •'Blake,'' Lieutenant -Commander C. D. Sigsbee, U. S. N.. Commaxdixg. 
Date. May lOtli. 187(i. ^'^"•^^° 'j1;][; Xn. of Position, 3. No. of OB.sBJiv.iTJo.y. 1, Lj-we Letter, S. 



S.D. 
AUG. 

I.e. 

DIP. 
RBF. 

M COB. 
OBS.ALT. 

2d COS. 


- 


1 50 C. F. 
4 03 C. C. 


12-30-11.4 


DEC. (+) 
COR. DEC. 
P.D. 


t 32 2'f..l 


M. J) 


': COR 


.J?.^. 


i9-^--45.6 


M. D^ 


lS-37-18.9 
+ 1-19.4 


90° 00' 00" 


1! 

\\COR 






+ 


81 27 40 :' 


1 


R.A.M.S. 


---— — 


.rnn\r DIP— BY ANGLE 
i WITH SEXTANT. 


32 oT 29 

1 




R. A. M. S. 


.105 


: 180° 00' 00" 
For SECONDS. 3 Z. D. 










3-13-37.474 


LOC.iL. OIFF. 

\ iDIFF.= 
11 •°^^- 








T. ALT. 

P.D. 
SVM. 
i S13I. 
T. ALT. 
HEM. 

H.A. 
M.A. 

Ji.A.MEB. 
E.A.M..S. 
L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


28 20 00 L.SEC. 
81 27 40 L. COSEC. 


T UT 


o - // ' 


.'00484 
9.50189 
9. 79554 


HOB. PAR. 
TAB. XIX. 

smr. 

CONST. 
2d COR. 




.0.5542 
.00484 

9. 50565 


LAT. 
P. D. 


28 40 00 
81 27 40 


L. SEC. 
L. COSEC. 

L. COS. 




71 18 54 L. COS. 


smi. 

i SUM. 


142 57 48 


59' 4S" 


9.79395 


REM. 1 ' 
H. A. 






"; 


28 46 L. SIN. 


38 38 46 1 i 

_ 
3-48-30 1 


. SIN. 




8-43.7 /,. SI.X. i. 


19. 35986 
9. 67993 


•S 1 19.35906 
.SIN.h 9.67953 


CHARACTER OF 
OBSERV'N. 


19^4-45.6 




R. A. ] 
if. .4. MER. 
R.A.M.S. 
L. M. T. 1 

LONG. T. 


9-44-45.6 




Ver,/ good. 
Mod'Vli/ good. 
Barely uccept- 


3-13-37.5 
12-42-24.4 


3-13-37.5 






2-42-38.1 


1 OBJECT. X 


5-56-13.9 
89° 03 '28" WEST. 


5-56-00.2 




VEST. 


■ YALl-E OF 

1 0-BS'i^-l 







DEFINITE POSITION ON THE ABOVE LINE AT THE TIME OF OBSERVATION: 
Latitude 28° 38' 35" Nomtb. Loxgitvde 89" 00 15" West. 



Patent-Log 21.35. 

Carried Observation 2 back, by cm 



with Observation 1, for Definite Position on Observation 1. 

[OVER.] 



198 DEEP-SEA SOUNDING AND DREDGING. 

BE MARKS— { Continued). 



OBSERVER Robert G. Peck, Master, U. S. Navy. 

COMPUTER same. 



PRELIMINARY WORE. 


TIME AS PER SOUNDING-SHEET 12h 41'" A. M. P. M. 


TIMES. 


ALTITUDES. CHRO. COMPS. 


HEM J RES. 




12-37-13 

48 
38-27 

41-10 


3°2 314S 

58 oO 

14 10 
26 00 


r—w. 

CO. 

a 
w. 

o-ir. 
c. c. 




OBJECT 

HORIZON _ 


—mod. good. 




COMP. BEARING OF OBJECT...,. 
SHIP'S HEAD. 


S'l & E^i. 

21.35. 






Taken (hiring Sounding Na. 
Taken shortly before Sounding No. 

Taken between Soundings Nos. 


3&4. 


80 


402 20 


12-39-11.4 


32 57 29 







199 






FORM 8. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

SUJIXER'S METHOn BY MOON, JPLAXET ( ), STAR (Vega). 

™o.u Lat. -29° 01' 40". LuxG. 89° 02' 35". ro L.iT. 2iP 5«' 25" Lo.xg. 89° 04' 35". 
r SmvEY Sth. "Blake," Lieutenant - Coimuaiider C. D. Sigsbee, T'. S. N., Co.vjirA.wiNO. 
;, May 10th, 1876, ^-" *''° pfj .\o. of Pu.-<rno.s. 4. No. of 0,s.sfhv.u-io.x. 2. Lixii Letter. S. 



S.D. 

L C. 
DIP. 
BEF. 

OBti.ALT. 


- 6 29 


W. T. 

C.F. 
C.C. 
G. M. T. 

G.D. 


12-45-13.' 1 
5-58-07. 8 


DEC. (-1) 
CUB. 
COB. DEC 


38 39 49 




COB. 


18-32-46. 2 


31. D.— 


18-4,3-20.9 


90° 00' 00" 




1 COB.B.A 




18-44-10.3 
9a + 


51 20 11 








S. A. M. S. 
Co,: G. 31. T. 

B.A.M.S. 


s-io-ss'.'ti 

. 110 


For G. 31. NOON 


niP—BY ANGLE 
WITH SEXTANT. 


FOB H. d- M. 


180° 00' 00" ! 




For SECONDS. •• >^-//;,^ 






3-13-38.46 










i DIFF.^ 
; DIP. 





T.ALT. 

LAT. 

P.D. 

SU3I. 
i 8VM. 
T.ALT. 
BE3I. 

H.A. 
B.A. 

B.A.MER. 
B.A.3I.S. 
L. M. T 
G. M. T. 
LONG. T. 
LONG. A. 


57 22 17 
51 20 11 


L. SEC. 
L. SIN. 


.05542 
. 10744 

9. .56368 

9. 28638 


LA'i: 
P.D. 

Sim. 

i SU3I. 
T.ALT. 

H.A. 
B.A. 

B.A.MEB. 
B.A.M.S. 
L. 31. T. 
G. 31. T. 
LONG. T. 
LONG. A. 


57 22 17 


L. SEC. 
L.roSEf. 




HOB. PAB. 




.05679 'I'AB.XIX. 
. 10744 

9.29274 M COB. 




137 02 28 


68 41 14 


00' la" 


11 08 57 
2-29-46. 3 


11 18 57 




L.SIN.i. 

WEST. 


19.01292 
9.50646 


18-32-46.2 


L. SIN. i. 


9.01743 


CHARACTER OF 
OBSERV'N. 






Very good. 

Mod't'y good. 

Barely accept- 
able. 


16-02-59. 9 
3-13-38. 5 


16-02-11.2 
3-1,1-38. 5 


12-49-21.4 
18-44-40.3 


12-48-32. 7 
18-44-40. 3 


OBJECT. 

HORIZON. 

VALVE OF 
OBFN. 


i-'^ 


5-55-18.9 
88° 49' 43" 


5-56-07.6 



DEFINITE POSITION ON THE ABOVE LINE AT THE TIME OF OBSERVATION: 
Latitude 28° 37' 25" Nortit. Longitude 89° 00' 10" West. 

REMARKS. 



Rati 



._22.4. 



l,byc< 



le and distance, tc 



nth. Observation 2, for Definite Position on 



200 DEEP-SEA SOUNDING AND DREDGING. 

BEMABK8 — ( Continued). 



OBSERVER ., Robert G. Peck, Master, U. S. Navy. 

COMPUTER same. 



PRELIMINARY WORK. 




TIME AS PER SOUNDING-SHEET 12» 47™ A. M. P. M. 




TIMES. 


ALTITUDES. CHRO. COMPS. REMARKS. 




45-08 
47 - 23 


°7 ,14 30 






T,i,„I .-,,n(l_ 


14 lU 
21 00 

27 30 . 
44 30 


C—W. 
CO. 

a 

G—W. 
0.0. 


HOmZON " " 1 






.....A 


SHIP'S HEAD. 




Trden diirimj Sounding 17u. 

'J'uken shortly after Sounding No. 

Talcen between Soundings Nos 


3 & 4. 


02 201 20 


12-4-1-13.1 


57 28 46 







FOEM !). 



[On this form the Italics show 



201 

iresented by Eomaii.] 



1 matter uf the blank form, while the written or recorded m 

FORM 9. 
U. S. COAST SURREY. OFF-SHORE WORK. GULF OF MEXICO. 

SUMNER'S METMOn BY MOOX, PTjAXET {S:iUu-n), STAR ( >. 

Li.wE FROM L.a: 29° 01' 40", Lo.xg. 89° 02' 35", to L.xt. 2fio 58' 25", Lo.wa. 89° 04' 35". 
Co.isT SuHYEY Str. "Blake," Lieutenant - Uommander C. D. Sigsbee, U. S. N;, CoMM.iyniKa. 



Dat 


g.Mav 10th. 1876. ^^^°"j!;j;^:J\ 


^0. OP POSITIO 


',5. No. 


OF Observation, 3. Line Letter 


s. 


S.D. 
AUG. 

I. a 

DIP. 
REF. 

M COR. 
OBS.ALT. 

2d COR. 


- 


1 50 
720 


W.T. 
C-W. 
C.F. 

G. M. T. 
G.D. 


4-23-1g!5 
5-58-09.2 


DEG.{-) 
i COR. 
' COR. DEC. 


+ 4.6 


M.D. — 2.9 y.R.A. 
~^-^ \\COR. 


2°2 36 46^56 
— .94 


ilf..D. + .583 

—.162 

583 


9-21-25.7 

+ 1-19.3 


10 23 45 

90° 00' 00" 


4.0 


COR.R.A. 


22-36-45'.G2 


22-22-45 


P.D. 


100 23 45 


.944 


9^ + 


R. A. M. S. 
Cor. G. M. T. 

B. A. M. S. 


3-14-30.27 

— 15.935 

— .041 


For G. 31. NO ON. 
FOR H. & M. 
For SECONDS. 
LOCAL. 


DIP— BY ANGLE WITr\ 
SEXTANT. 1 


32 43 45 


$Z.D. 
BOR. 

DIFF. 
\DIFF.^ 
DIP. 


180° 00' 00" 








3-14-14.3 









T. ALT. 

LAT. 

P.D. 

SUM. 
iSUM. 
T. ALT. 
REM. 

H.A. 
R.A. 
R.A.MER. 

r'.a. M. S. 

L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


3°2 3'6 25 
2S 00 00 
100 23 45 


L.SBC. 
L.COSEC. 

L. COS. 

L.SIN. 


. 05407 
.00718 

9.21755 

9. 87035 


T. ALT. 
LAT. 
P. D. 

STJM. 
iSVM. 
T. ALT. 
REM. 

U. A. 
R.A. 

R. A. MER. 
R.A.M. S. 
L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


32 3^ ik 
28 20 00 
100 23 45 


L. SEC. 
L. COSEC. 

L. COS. 

L. SIN. 


.05542 
.00718 

9. 87149 


SOR PAR 






TAB. XIX. 

SV3I. 
CONST. 
2d COR. 




161 00 10 
80 30 05 


161 20 10 
80 40 05 


59' 1,2" 


47 53 40 

2-5°6-25.7 
22-36-45.6 


h. m. a. 

2-55-20 




L. SIN. i. 
WEST. 


19.14915- 
9. .57457 


L.SIN.i. 
WEST. 


19. 14402 
9.57201 


CBABACTEB OF 
OBSEBV'N. 




1 

1 


I 
1 


p 

s 


19-40-19.9 
3-14-14.3 

22-22-45.0 


19-41-25.6 
3-14-14.3 


16-27-11.3 


OBJECT. 

HORIZON. 

VALVE OF 
OBS'N. 




X 
X 




5-56-39.4 
89° 09-51" 


5-55-33.7 
88° 53' 25" 







DEFINITE POSITION ON THE ABOVE LINE AT THE TIME OF OBSERVATION : 
L.iTiTUDE 28° 14' 15" North. Longitude 88" 5803" West. 



Patent-Log, 44.6. 

Carried Observation 4 back, by cc 



with Observation 3, for Definite Positi 



202 DEEP-SEA SOUNDING Ai^D DEEDGING. 

BUMAEKS— {Continued). 



OBSERVER Robert G. Peck, Master, U. S. Navy. 

COMPUTER same. 



PRELIMINARY WORE. 


TIME AS PER SOUNDING-SHEET 4I' 25'" A. M. P. M. 


TIMES. 


ALTITUDES. 


CHRO. COMPS. 


REMARKS. 


4-22-56 
23 -37 


3°2 40 10 


V. a 

c. 
w. 
c—w. 

a a 




OBJECT - - - 

HOBIZON 


—mod. good. 


33 


87 30 








SHIP'S HEAD. 


44.6 

5&6. 


4-23-16.5 






PATENT-LOG 

Taken shortly he/ore Souadmg No. 
Taleen shortly of ter Sounding No. 
Taken between Soundings Nos 







FORM 10. 



203 



is foi-m the Italics show tlie printed matter of tlie bhink form, while the written or recorded matter is represented by Eon 

FORM 10. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

SiryrXJEH'S jftETHOJD JtY MOON, JPLAXET (Jniiiter), STAR ( ). 

Li.vE FROM La t. 290 or 40", Long. 89° 02' 35", ra La t. 2l50 58' 25", LoTiu. 89° 04' 35". 
Coast SvnvEY Stk. "Blake," Lieutenant -Commander C. D. Sigsbee, U. S. N., Commanding. 
Date, May 10th, 1876, ^'J^'Zjp.M. ^°- of Position, 6. No. op Ohservatiox, 4. Line Letter, S. 



S.B. 
AUG. 

I.e. 

DIP. 

1st COlt 
OBS. ALT. 

M con. 


O W, 




h. m. ,,. 


[1 




o , „ 




M. D. - 4.01 


F- 




1,. „,. ,. 


Jir.D.— 1.285 


— 1 50 
14 17 50 


G-W. 
C.F. 

a a 

G. M. T. 
G.D. 


4 33 10.2 |i^^...^ 1 




~ 1.45 


COB ' ' ^ - 


-1.45 
1.285 














10-31-20 
+ 1-19.4 


00° nr uo" 


]'i;,l COB.B.A 


15-44-13. 6 


22-32-39.4 


-1 
IP.D. 


108 40 r,\ 


-f5.8l!! 


-1-1.863 


B.A. M.S. 
i Cor. G. M. T. 

" 
! B.A. M.S. 


.3-{i-3.;:27 


For G.M. NOON 
FOB H.AM. 
For SECONDS. 

LOCAL. 


DIP— BY ANGLE WPFH 1 
i SEXTANT. \ 


2. Z. D. 
HOB. 

DIFF. 
h DIFF.^ 

: DIP. 


m° 00' ofi' 






3-14-15. 9 










T.ALT. 

LAT. 

P.O. 

SUM. 

iSUM. 

T.ALT. 

BEM. 

H.A. 
B.A. 

B.A.MES. 
B.A. M.S. 
L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


U 08 22 
108 40 51 


L.SEC. 
L. COSEC. 

L. COS. 

L. SIN. 


.05407 
.02350 

9.40123 


T.ALT. 

LAT. 

P.O. 

SUM. 
iSUM. 
T.ALT. 


14 08 22 
108 40 51 


L.SEC. 
L.COSEC. 

L. COS. 


.02350 
9. 94295 


HOB. PAB. 
TAB. XIX. 

SU3I. 
CONST. 
2d COB. 






75 24 36 


151 09 13 
75 34 36 


59' 42" 


61 16 14 

4-07-23. 2 
15^4-13.6 




BEM. i 61 26 14 




L. SIN. 




L.SIN.i. 
WEST. 


19.42175 
9.71087 


_£_! ,^«-*2"^ 


CBARACTER OF 1 
OBSERV'N. \ 


B.A. 

B.A.MEB. 
B. A M S. 


15-44H3. 6 


J...-.JiV.5.1 ». (iUB( 




.:ii 


19-51-36.8 


3-14-15. 9 






1 
1 


l;l 


L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


16-37-20.9 
22-32-39.4 


16-36-27.2 
22-32-39.4 


OBJECT. 

HOBIZON. 

VALUE OF 

OBS'N. 


■ 


X 




5-55-18.5 


5-56-12.2 




WEST. 







DEFINITE POSITION ON THE ABOVE LINE AT THE TIME OF OBSERVATION: 
Latitude 28° 12' 25" North. Longitude 88° 58' 00" West. 

BEMABKS. 



Patent-Loo 46.4. 

Carried Observation 3 forward, by course and dist 



. 4, for Definite Position on Observation i. 

[OVER.] 



204 



DEEP-SEA SOUKBING AND DEEDGIKG. 

BE MARK 8— {Continued). 



OBSEEVER Kobert G. Peck, Master, U. S. Navy. 

COMPUTER same. 



PBELIMINABT WORK. 


TIME AS PER SOUNDING-SHEET 4^ 35™ A. M. P.M. 


TIMES. 


ALTITUDES. 


CHBO COMPS. 


REMARKS. 


4 -31- 39 

3.i-02 

33-57.5 

34-54 


14 34 10 
26 40 
20 20 
09 20 

13 58 40 


c. 
w. 

G-W. 

a a 

c. 

CO. 




OBJECT 

HORIZON 

OOMP BEARING OF OBJECT 


good. 




SHIP'S HEAD. 






Taken during Bounding No. 
TaJcen shortly before Sounding No. 




51 


89 10 


4-33-10.2 






TaJcen between Soundings Nos 





205 

ted by Roman.] 



FORM 11. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

aVMNEWS METHOD BV SUN. 

'ROM Lat. 29° 01' 40", LoxG. 89° 02' 35", to Lat. 26° 58' 25", Loxa. 89° 04' 35". 
SuRvjn- St/i. "Blake," Lieutenant -Commander C. D. Sigsbee, II. S. N., CoMMA.vDiNa. 
No. OF Posmox, 7. No. of Observation, 5. Line Letter, S. 



S.B. 
PARX. 

I.e. 

REF. 
DIP. 
COR. 
OBS.ALT. 


+ 
+ 

+ 
52 


15 52 
06 
1 50 
43 
4 03 
9 22 
45 00 


IF. r. 

G—W. 
C.F. 
CO. 
G. M. T. 
G.D. 


r"' 


DEG.{+) 
COR. 
COR. DEC. 

P.D. 


17 47 17 
2 06 


II. D. +.38.7 
+ 3.27 
11.61 


EQ.ofT. 

COR. 

COR. EQ. 
OFT. 


0-34-7.75 


n. D. + .09 
+3.27 
+ .2943 


3-15-02.5 
1 19 5 


17 49 23 
90° 00' 00" 


3-48.04 


3-16-22 
104 + 


72 10 37 


+ 126.5 





TALT 

LAT. 

P.D. 

SVM. 

iSUM. 

T. ALT. 

REM. 

L.A.T. 
EQ. OF T. 
L. M. T. 
G. M. T. 
LONG. T. 
LONG. A. 


5°2 54 22 
27 40 00 
72 10 37 


L.SEC. 
L. COSEC. 

L. COS. 

L. SIN. 


.0.5273 
.02136 

9.37212 

9.60015 


T.ALT. 

LAT. 

P.D. 

SUM. 

4 smL 

T.ALT. 
REM. 

L.A.T. 
EQ. OF T. 

L.M. r. 

G. M. T. 
LONG. T. 
LONG. A. 


52 54 22 
28 00 00 


L.SEC. 
L. COSEC. 

L. COS. 

L.SIN. 


.05407 
.02136 

9.3G688 

9. 60305 


DIP-BY ANGLE 
WITH SEXTANT. 


2 Z. D. HOR. 
DIFF. 
i DIFF. = 
DIP. 


180° 00' 00" 


76 22 29 


153 04 59 






CH ABAC TEE OF 
OBS'N. 


23 28 07 

h. m. J. 

9-24^07 
3-48 


2.3 ,38 07 
9-24-18. 2 


L.SIN-.h 
WEST. 


9.04636 


L.SlNi. 
WEST. 


19.04536 




1 
1 


! 


1 


9-20-19 
3-16-22 


9-20-30.2 


OBJECT. 

HORIZON. 

VALVE OF 
OBS'N. 


X 
X 

X 






5-56-03 
.89° 00' 45' 


5-55-51.8 
88° 57' 57" 



DEFINITE POSITION ON THE ABOVE LINE AT THE TIME OF OBSERVATION : 
Latitude, ^1° 48' 55" North. Longitude, 88° 59' 25" West. 

BE MARK 8. 



..70.2 



:e foi-Wi 



a from Position Se.and hack from 
owing for time-intervals. 

[OVER.] 



206 DEEP-SEA SOinmiHG AKD DREDGING. 

REMARKS— {Continued ). 



OBSERVEE Roberta. Peck, Master, U. S. Navy. 

COMPUTER : same. 



PRELIMINARY WORK. 



TIME AS PER SOUNDING-SHEET, 9b 15"^ A. M. _ 



ALTITUDES. 



CHRO. COMPS. 



3-14^39. 
15-02. 



SUN 

HORIZON. 

COMP. BEARING OF ,STi\' _„_ 

SHIPS HEAD. 

PATENT LOG 

Talien during Sounding . 

Taken shortly before Sounding No. 



G-W. 
C.C. 



Talcm befioe 



onndings Noe. 



FORM 12. 



207 



FOKM 13. 
U. S. COAST SURVEY. OFF-SHORE WORK, GULF OF MEXICO. 

MERIItlAX ALTITUDE OF SVX, UOOX, VI.AXET ( ), STAR ( ). 

Like from Lat. 29° 01' 40", i-.-w;. 89- 02' 35", to i.ir. 26° 58' 25", Long. 89° 04' 35". 
Coast Sujivey Stu. "Blake," Lieutenant - Commander C. D. Sigsbee, U. S. N., Commaxding. 



; 9. iVb. OF OasERTi 

FORM FOE SUN OR STAR. 



6. LiiVE Lettes, S. 



OBS. ALT. 
COR. 

T.ALT. 

Z.L. 

DEC. 

LAT. 


80 06 50 
9 52 


S.D.^ 
, P.17?A-. + 

I.C.— 

REV.— 

DIP. - 
COR. + 


15 52 
02 

1 50 


DEC. (+) 
COR. DEC. 


17 47 14. G 
3 48.8 


H. D. + 38.6 

LONGT.+ 5.93 

193.0 

34.7 

! 1.1 


CHABACTEB OF 
OBS'N. 




! 
1 


r 


8U 16 42 


17 51 03. 4 






+ 222. 8 


SUN. 

HORIZON. 

VALUE OF 

OBS'N. 


X 
X 

X 




9 43 IS 


DIP— BY ANGLE WITH SEXTANT. 




'2Z.D. 

DIFF. 

i DIFF. = 
DIP. 


180° 00' 00" 




27 34 21 


1 




■ 











OBS. ALT. 








H.P. 
TAB. XIX. 




G. M. PASS. 
COR. LONG. 

L.M.PASS. 
LONG. 

G.M.T. 




M.RET. 

LONG. 




AUG. 

LC. 
REF. 






2d COR. 
T.ALT. 

Z.D. 










90° 00' 00" 


DIP. 
M COR. 


SIM. 










CONST. 


59' 42" 


DEC.i ) 

COR. 
COR. DEC. 




M.D. 










DEC. 




i 




LAT. 



















DEFINITE POSITION ON THE ABOVE PARALLEL AT THE TIME OF OBSERVATION: 
Latitude 27° 34' 21" North. Longitude 89° 02' 30" West. 

REMARKS. 

Patent-Log 85.4 

with Observation 6. ] 

[OVEB.] 



208 DEEP-SEA SOUNDING AND DEEDGING. 

EE MARK 8— (Continued). 



OBSERVER Eobert G. Peck, Master, U. S. Navy. 

COMPUTER same. 



REMARKS. 


TINE AS FEB SOUNDING-SHEET A. 31. 


P. 31. 


Noon. 


OBJECT __ __ . . . . 




rood 


HORIZON . ...._.. " 




SHIP'S HEAD. 






PATENT-LOG 






TAKEN DXmiNG SOUNDING NO. 






TAKEN SHOBTLT BEFOBE SOUNDING NO. 






TAKEN SHOBTLT AFTER SOUNDING NO. 






TAKEN BETWEEN SOUNDINGS NOS 




9& 10 









May 10- 
May 10- 



5". 

a. 

re. 



Second column of remarls. 
(Descnhing the manner of getting ecLch position, <^-c.) 



May 10_.- 
May 10— 

May 10— 

May 10— 

May 10- 

May 10_. 

May 10- 

May 10- 

May 10_- 



Form 13 (A). 

U. S. COAST SURVEY. 

Off-Shore Soundings^ Gulf of Mexico, 

PLOTTING FORM. 

LINE S, FROM near South Pass, Mississippi River. TO latitude 26° 58' 25", longitude 89° 04' 35". 

IN STEAMER '-Blake," Lieutenant-Commander C. D. Sigsbee. U. S. N., Assistant C. S., COMMANBINa. 

REG- UN AT 8 HOURs 40 MINs. p. m.. DATE May 9th, 1876, ENDED AT 7 HOURs 24 MIM. p. m. DATE May 10th, 1876. 



Tirr OBSi J r itio 



^' I 



IfM i tMlE rOSMlIO\S 



""'fY,'" Itititmle /oiif/ifiuU 









Second column of remarks. 
Describing the manner of gettiny each position, tf'C.) 



May 10 

May 10 

May 10 
Blay 10 

May 10 te 

( 

May loJp' 

May 10, -r 

May 10. 

May 



and distiince, to an Intersection with Oba. I (1) for Def. Pos. on Obs. I (1). 

I distance, to an intersection with Obs. II (2) for Def. Pos. on Obs. II (2). 
distance, to an intersection with Obs. Ill (3) for Def Pos. on Obs. Ill (3). 
nd distiince, to an intersection with Obs. IV (4) for Def Pos. ou Obs. IV (4). 



=■ and distance forward frou 
s thus found, allowing for 


I Pos. .Ss and back from Pos. Ss. 


Jl.s. VII (7) back to an i 
des thus found, allowing f 


itersi'ction with Obs. VI (6). 
or time-intervals. 


urse and distance forwar 
les thus found, allowing fo 


from Pos. Ss and back from Pos. Sio. 
r time-intervals. 



(8), XI (9), and XII (10), gives Def Pos. on Obs. X (8). 
8), XI (9), and XII (10), gives Def Pos. on Obs. XI (9). 
(8), XI (9), and XII (10), gives Def Pos. on Obs. XII (10). 



Form 13 (B). 

U. 8. COAST SURVEY. 

Off-Shore Soundings, Gulf of Mexico, 

PLOTTING FORM. 

LINE 8, FROM near South Pas^i. Mississi))jii River. TO. latitude 26° 58' 25", longitude 89" 04' 35". 

IN STEAMER "Blake," Lieutenant-CoiumaLidci' C. D. Sigsbee, U. S. N.. Assistant C. S., COMMANDING. 

BEGUN AT 8 HOURs 40 MINs. p. m., HATE May 9tli, 1876, ENDED AT 7 IIOURs 24 MINs. p. m., DATE May 10th, 1876. 





Time <-/ <Ar oUcrva- 


THE OBSERVATIOJf. 


'I- 


Courses and distances from freviom ohservation 
or ehangeof the course. 


DEFINITE POSITIOXS. 


First eolvmn of remarks 
ilo guide in plMing). 




DATE. 


.... 


«,„. V5r 




«- }e^e^' r:^ 'Xl 


Serial 
l)OsitinnH 


Second column of remarks. 
iDeseribiug the manner of.,e,limj earl, fosition. ,fr, ) 




1 , :„,„:.,„ 






1 


-}BMmmm- 




' """ 


■J7 1 PM 


~- 




:;:--■■■-- :: ci: i :: 


Position oOtalnedb, 11,. bearings 


M«y 10 




-"■ 


„ ,. , , , „. .. 


C»mrf 01». n (2) back, b, cou™> and dlsan.o, >o an Into-Kti.n »Ub Ob.. 1 (1) for D.f. Pc. on Ob.. 1 (1). 




■ j 


cari«i I f -db ^ dd 1 1 nob.iiwr II rp ob.iiw 


""^ '" 


-- •---: "■ , ' ,£^;;s.ss^ 


40.4 




L ' I. , nrP 0b.n.(3, 










35 


i 








4 ^'7 1 












^ 


g s. s 


s s? ^? 






7;;: -j; ■ ' ^^' 




V......J V. 


:::..:::i ;: ::: :: :: 


— --- — 


"v:;: ■:;-:;:ii;;l'""-"""'' 


! 




80 05 0.-, 

z s s 

80 01 13 




10,3 


r 1 |, , ,; „|.M.S.audl«krn>IIlI><».S». 


""""- 1 M^"" 


■'"" -- ' ' "" : ■ 


.. ..Chan e«ft..e course- 


miccM: Filed io 111. Alcblvc 1 






1 1 




„.„,...-»! 




^ , F 




.0.3 


. .0 ,« .» «» .. .. 






May 10 ' sn 1 P.M. 


Oipollii 


VG \II 10 


Sounding Sfn. 


r 1— .. 




*'•'■" -- ' i "'■ j •'■■'"■ 




Tb. lnu.™»tl„n or 0b»™u«„. S(8).X. (C.-nd X.1 ,101, irt™ B-f. P... "» Ob.. XII (10). 






































! 
1 



FORM 14. 



'p#? 


ees of Temperature- 


Fohrenlieil 


1 




^4^ 




m 


1 


S 




por 1 1 i ; 








-^ 




BS 1----Tr 


-jWj^ — j^ y |-l- — — r 


z^^zz-: 


i^r 


^- 




i±i t^i^ 


^^^sig^ 




g: 


=: 




g,o[i-}-|nT|| 


^-^^ir^^^ 


::S: 


=^- 


5: 




^ zHzh _J;i/:. 


-M/H"' ' ' p ~h — ^ — 




:::: 


i: 




6^, ! i 1 1 1 71/ 


yi • ■ ' ' 1 '" ! ■ " 




::: 


li 




3 "''^ tFi/^ 


i"T^^-^--lf I- 




-?= 


= = 




^"1^ =w 


1 — V'ti^"' — ^^ — 1 — 


- 1 1 1 1 - 


:S 


:^ 




£" {--j -W-L '- 




"i 


■ri}: 


-^ 




R -4-H-|ff- 


^r"^ i llTt 




:J 


+T 




^ 1/ i 








:_L 






::::::+:::$:::::: 




::: 


IZ 










--T 


— ^ 




M'lp 






::: 


i: 




K 






iiji 


:ir 




-3 E? 


ip-^OTii 


:::±:: 


::: 


" 


= 


.oo:|:: ::S 


— I ij: 




iiti 


:: 














■ ■" "H" 






::: 


i: 




I 






— 


-- 














^J4[[^ 


#]4MFlwt 




:ih: 


^4= 




asi" 











TEMPERATUR.E CURVES AT EACH STATION 
ON LINE S. OF 1875- 6., GULF OF MEXICO. 



SUPPLEMENT. 



stjf'fle:sie;?^t. 



rilK SIGST5EE MACHINE FOR SOUNDIXG WITH WIRK; PATTERX OF issi. 

During the year 1881 a Sigsbee Suundiiig-Machiiie was niatle for eacli 
of the following-named organizations: U. S. Navy, U. S. Coast and Geodetic 
Survey, and Imperial German Navy. Another is now being made for the 
U. S. Commission of Fish and Fisheries. The leading object in this sup- 
plement is to point out such improvements in these machines as are not 
embraced in the machine shown on Plate 8, (fcc, of the original volume lo 
which the supplement pertains. 

The references herein relate to the original volume. In the views 
shown on the two accompanying Plates the scale of dimensions is the 
same throughout the set. 

In the construction of the new machines metal only has been em- 
ployed, a cast-steel bed. in two parts, replacing the wooden bed formerly ■ 
used. The new style of bed allows the machine to be more compactly 
folded than before.^ The strain-pulley has been abandoned and its former 
place on the bed is now occupied by the steam-engine and a special 
form of tightening-pulley.'- An auxiliary brake has been placed beneath 
the reel: a single spur buffer only is used at the foot of the guide-pipes, 
and the outriggers to which the side stays are set up. and the casting 
which su])ports the fairleader and swivel pulley, are now hinged or 
pivoted.' The intention is to adapt the machine for folding with the 
removal of so few parts that, ui inexperienced hands, there need be no 
doubt as to the position Avhich each part should occupy when the machine 
is set up for use. Steel castings are used wherever they can l)e utilized. 



mp. Plate 1'2. -Page 62, M A, ami p. 7-2, H 1. 



212 SUPPLEMENT. 

Plate 42 shows the right side of the machine. In Fig. 1 the machine 
is rigged for reeling in by steam, tlie reel being connected with the engine 
by means of a belt of round leather on one part of which rests the tight- 
ening-pulley.^ The swivel-pulley is down in the position it would have 
when reeling in while the ship has headway.- Fig. 2 shows the machine 
in temporary disuse, as in port, for instance. The reel, being unshipped, 
is supposed to be in the tank containing preservative.^ The register is 
thrown back out of the way.* The fairleader arrangement is thrown back 
on its pivot and the swivel-pulley is carried still farther to the rear on 
another pivot; neither are unshipped. The side stays are slacked and 
their outriggers are thrown up on pivots' into a snug position." The two 
parts of the back brace or stay are disconnected, and the upper section of 
the guide-pipes is thrown back where it remains supported, all parts of 
the machine thus being accessible for cleaning. 

Plate 43 shows the Icft side of the machine. In Fig. 1 it is rigged for 
paying "out.*" The belt is disconnected and the friction-line is applied. 
The swivel-pulley is laid aside, resting on the left outrigger. The clamp 
is in use in the fairleader as if the reel had been stopped temporarily to 
repair a defect in the wire,^ Fig. 2 shows the machine folded for trans- 
portation or stowage, the reel being in the tank. The cross-head pulley 
has been removed, but the cross-head itself remains in place. ^ In folding 
the machine the reel and this pulley are the only parts that do not remain 
hinged or otherwise attached to their proper places ; such bolts or screws 
as are necessarily removed are again replaced, after the machine has been 
folded, to secure them against loss or error in future adjustments. The 
front part of the bed has been thrown upward, carrying with it the guide- 
pipes. The guide-pipes are folded in a reverse way from ihat shown in 
Fig. 2, Plate 42, while the outriggers, fairleader arrangement, and swivel- 
pulley are folded as shown in that figure. For inclosing the machine 
when folded, a box is placed over it and screwed to the wooden piece 
shown by the figures of Plates 42 and 43. This wooden piece forms the 



' Comp. Plates 7 ami 13. '^ Page 81, t 2. ^' Page 34, IT 5. ^Page62, 113. 

"Comp. Plate 12. « Page 67, H 5. • Page 77, IT 2. sPage 63, 1[ 2. 




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SUPPLEMENT. 213 

bottom of the box, but, for coiiveiiieiice, il is pormanently attached to the 
steel bed. The outside dimensions of the l)()x. when il is made of lieavy 
stuff, are as follows: length. 4 feet o inches; ])readlli. 1 foot S inches; 
heiglit, 3 feet. In tliis space are stowed such conveniences as tlie steam- 
engine, tigiitening-pulley, accumulator, dynamometer, governor, swivel- 
pulley, auxiliary brake, etc.^ 

The bed is well shown in the several ligiues of Plates 42 and 43. It is 
composed of two skeleton frames of steel, hinged together by bolts. The 
steel bed does away with the \varping sometimes experienced with the 
wooden bed when exposed to a hot sun. Warping of the bed throws the 
standards of the reel out of alignment, which makes the axle of the reel 
bind in its bearings. 

The enaine does uot ditfcr essentially from that shown on Plate 18, 
with the exception of being vertical instead of inclined.' 

The tigtitening.puiiey? A collar, sHdiug ou tlie Vertical shaft shown in 
the plates, has a stud on one side which forms the axle for the pulley. 
The tension on the belt is maintained by the elastic pressure of a si)iral 
spring. Along the shaft are bored holes at regular intervals, into any one 
of which the pin shown near the top of the shaft may be inserted accord- 
ing to the amount of pressure which it is desired the spring shall exert. 
When the tightening-pulley is not in use the shaft is turned on its axis, 
carrying the pulley to the left side of the machine, giving place for the 
standing part of the friction-line, or the spring scales — Fig. 2, Plate 42. 
and Figs. 1 and 2, Plate 43. A pin at the foot of the shaft keeps the latter 
from turning when it should remain immovable. 

Tite outriggers are oT cast-stecl; each is fastened or hinged to the bed 
by a bolt going through a longitudinal slot in the outrigger.^ In use the 
inner ends of the outriggers rest upon studs projecting from the bed. 

The anxiiinry hrahe and its ttse. — The brake is a lever of the first order, 
pivoted on a block screwed to the board shown on the plates. The end 
of the lower arm, which is fitted with a wedge-shaped piece of wood, may 
be pressed into the V-groove of the reel by force applied to the other arm, 

1 Comp. p. 67, nil 2 and 3. -Page 87, H 2. ^Comp. p. 86, H 3. •'Corap. Plates 8 and 12. 



214 SUPPLEMEl^T. 

but, in the absence of such force it is held out of action by a spring. The 
auxihary brake serves for immediate and temporary use in the event of 
the friction-hne or the connecting-belt parting, and in unusually heavy 
seas and under adverse circumstances it may be used in lieu of the toggle 
tucked into the friction-line — described in the original volume. The office 
of the toggle — although it is rarely used — is to impose upon the reel a 
small amount of friction which will not be lessened by the action of the 
governor,^ the object being to permit in heavy seas a rapid rate of paying 
out.^ The occasional advantage which may be derived from this acces- 
sory is well illustrated by such an extreme case as would make the use of 
the auxiliary brake desirable, thus: sounding from the bow; sea heavy; 
ship pitching violently; a heavy reel in use, and containing a large coil' 
of wire which adds much to its weight at the periphery.' Under these 
conditions, and when the reel is revolving with considerable speed, the 
vessel rises suddenly, increasing the tension upon the wire which is 
being payed out; the cross-head is borne down, easing the friction-line, 
we will assume, more than is desirable, and the heavy reel, thus deprived 
for a second of nearly all frictional control, is set revolving with great 
rapidity. At this instant the vessel gives a quick, deep plunge. The 
reaction of the accumulator acting as a governor is almost instantaneous, 
and the friction-line is set hard taut ; but before the momentum of the 
heavy reel can be overcome the wire slacks and perhaps flies from the 
reel. If, in the case stated, the auxiliary brake, which is independent of 
the governor, had been bearing upon the reel with a constant pressure, 
maintaining a .slight resistance, the undue slacking of the friction-line 
would not have been followed by such excessive' revolution of the reel. 
To insure an even pressure of the auxiliary brake, the inboard end of the 
brake-lever — the long arm — might be connected with the bed of the sound- 
ing-machine by a spring of rubber or metal which could be set to any 
desired tension. It must not be inferred that the auxiliary brake is a 
necessity; it is intended as a convenience on extraordinary occasions, to 
obviate the necessity for unusual skill or judgment on the part of those 

1 Page 68, If 6. ^ Page 70, II 2. ; ■' Page 56, If 1. 





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> 

H 
W 

CO 



SnPPLEMENT. 215 

operating the machine. It has been my purpose to add to the sounding- 
macliine, when wai-ranted by economy, every appliance which may save 
time or prevent accidont. In many localities there is but a small propor- 
tion of weather during which astronomical observations can be had for 
determining the positions of soundings; it is therefore highly imporlant in 
such localities to make the hest use of favorahle weather. 

GRAVITATING OR COLLECTING TRAP FOR OBTAINING ANIMAL SPECIMENS FROM INTER- 
MEDIATE DEPTHS. 

In the original volume, page 144, last paragraph, and page 145, foot- 
note, reference is made to the invention of an apparatus for collecting 
animal forms from intermediate depths. The apparatus has now been well 
tried and a full description of it by myself (accompanied by a drawing), 
and a statement of the results obtained, by Prof. Alexander Agassiz, is 
contained in the "Bulletin of the Museum of Comparative Zoology at 
Harvard College, Vol. VI, Nos. 8 and 9, September, 1880."' 

1 quote a part of my own description contained therein, as follows: 

''The old practice of dragging for animal forms at intermedia] depths 
by means of a tow^-net, which, during the several operations of lowering, 
dragging, and hauling back remained open, was not regarded by Prof. 
Alexander Agassiz as affording acceptable evidence of the habitat of such 
specimens as were obtained, and he frequently referred to the subject 
during our association on board the ''Blake"" in 1878. 

"In March, 1880, it having been arranged that Professor Agassiz 
should make another cruise on board the " Blake, "" Commander J. Pi. 
Bartlett, U. S. N!, commanding, he asked my co-operation in devising an 
apparatus to meet the rigid demands of the work in question. This 
resulted in the apparatus described herein, which is presented in the pre- 
cise form used with success by the "Blake,"" although, as may readily be 
seen, it is open to great improvement, especially in minor details. 

"The 'Challenger' had examined intermediate depths by means of 
tow-nets trailing from the dredge-rope while hauling the dredge or trawl. 
In such api'actice it miisl have been that the depths to which the nets 



216 SUPPLEMENT. 

were sunk depended in some degree on the amount of slack-rope payed 
out, and also on the strain upon the dredge-rope due to the resistance 
encountered by the dredge when dragging; it cannot, therefore, be said 
that strictly determinate depths were examined by that method, even 
assuming that the nets gathered nothing while being lowered and hauled 
back. 

"It occurred to me that by using an apparatus in connection with a 
line and lead, payed out vertically as in sounding, and by dragging verti- 
cally, instead of horizontally as formerly, there would be at least as much 
certainty with regard to depths as in the old method, and that simple 
mechanical devices could be invented to satisfy the conditions of the work. 
The scheme has been stated in my volume on 'Deep-Sea Sounding and 
Dredging' (p. 145, foot-note), as follows: 

"'Our plan is to trap the specimens by giving to a cylinder, covered 
with gauze at the upper end and having a flap-valve at the lower end, a 
rapid vertical descent between any two depths, as may be desired; the 
valve during such descent to keep open, but to remain closed during the 
processes of lowering and hauling back with the rope. An idea of what 
it is intended to effect may be stated briefly thus : Specimens are to be 
obtained between the intermediate depths a and h — the former being the 
uppermost. With the apparatus in position, there is at a the cylinder 
suspended from a friction clami^ in such a way that the weight of the 
cylinder and its frame keeps the valve closed ; at I there is a friction hiffer. 
Everything being ready, a small weight or messenger is sent down, which 
on striking the clamp disengages the latter and also the cylinder, when 
messenger, clamp, and cylinder descend by their own weight to h, with 
the valve open during the passage. When the cylinder frame strikes the 
buffer at h the valve is thereupon closed, and it is kept closed thereafter 
by the weight of the messenger, clamp, and cylinder. The friction buffer, 
which is four inches long, may be regulated on board to give as many feet 
of cushioning as desired.' " 

The trap was first ti-ied in Narragansett Bay, and soon after was used 
for the second lime at sea, several improvements having been made in 



SUPPLli^MENT. 217 

the meantime by Professor Agassiz and Commander Bartlett. I quote 
from the Bulletin again, this time giving Professor Agassiz's words : 

''On the 1st of July the Sigsbee cylinder was tried for the second 
time in Lat. 39° 59' 16" N., Long. 70° 18' 3()" W., in 260 fathoms of water. 
The surface was carefully explored with the tow-net to see what pelagic 
animals and others might be found on the surface. There were found 
Calanus, Sagitta, Annelid larvee, Hydroid Medusae, Squillee embryos. 
Salpge, and a few Radiolarians. The cylinder, filled with water which 
had been carefully sifted through fine muslin, was then attached to the 
dredging-wire, and lowered, so as to collect the animals to be found 
between 5 and 50 fathoms. The time occupied by the cylinder in passing 
through that space was 28 seconds. The cylinder was then brought up. 
and the sieves and gauze trap carefully washed with water, which had 
also previously been strained through fine muslin. The water was care- 
fully examined, and we found the very same things which had a short 
time before been collected at the surface with the tow-net and the scoop- 
net; nothing different was collected by the cylinder. The Pvadiolarians 
(two genera) were perhaps more numerous than at the surface. A slight 
breeze having sprung up after the surface collections had been examined, 
the cylinder was then sent down a. second time at this same station, so 
adjusted as to collect any animal life to be found from a depth of 50 to 
100 fathoms. Not only in this experiment, but in all the subsequent ones, 
the same precautions were taken in regard to straining the water which 
filled the cylinder at the start, as well as that used for washing out the 
sieve and the gauze trap. The messenger sent down to detach and open 
the machine occupied 21 seconds in reaching the (50 fathoms) point to 
which the cylinder was attached, and the cylinder then occupied 30 
seconds in passing to the stop at 100 fathoms. On examining the sieves, 
it was found that the more common surface things, Calanus, Sagitta, 
Annelid larva?, Hydroid Medusae, and Squillse embryos, were entirely 
wanting, and there were only two Radiolarians of the same species as 
those from 'the upper levels found after a careful scrutiny of the water. 
Nothing additional was brought up. The cylinder was then sent down a 
third time, lowered to a depth of 100 fathoms, the messenger sent down 



218 SUPPLEMENT. 

to open it (time occupied 45"), and the cylinder traveled from 100 to 150 
fathoms (time 45"), so as to collect the animal life to be obtained between 
these limits. On drawing up the cylinder and washing out the sieve of 
the trap, not only did we find that the water contained nothing different 
from what had been brought up by the cylinder from the lesser depth, 
but it did not contain even a single Radiolanan. 

"On the 15th of July, in Lat. 34° 28' 25" N., Long. 75° 22' 50" W., we 
tried the Sigsbee cylinder for a third time, in a depth of 1,632 fathoms. 
With the same precautions before and after using it, the cylinder was 
sent to collect first between 5 and 50 fathoms (time 30"). The surface' 
was somewhat ruffled, and but little was found on the surface beyond a 
few Crustacean larvee and Heteropods. The cylinder contained Hydroids, 
fragments of Siphonophores, pelagic Algae, Crustacean larvae, and Hetero- 
pod eggs; forms which -differed from these scooped at the surface, but 
were identical with the species found on previous days at the surface 
under more favorable surface conditions of the sea. Next, the cylinder 
was arranged to collect between 50 and 100 fathoms (time of messenger 
21" from surface to 50 fathoms, time of cylinder 40" to stopper from 50 to 
100 fathoms). The water was found to contain only a couple of Squillae 
larvae, similar to those fished up at the surface. The third time the cylin- 
der went down at this station it was lowered to collect from 100 to 150 
fathoms (time of messenger from surface to 100 fathoms 45", time of 
cylinder in passing from 100 to 150 fathoms 45") . The water when ex- 
amined contained nothing. No Radiolarians were found at this station, 
either at the surface or at any depth to which the cylinder was sent (150 
fathoms) . 

"The above experiments appear to prove conclusively that the sur- 
face fauna of the sea is really limited to a comparatively narrow belt in 
depth, and that there is no intermediate belt, so to speak, of animal life, 
between those living on the bottom, or close to it. and the surface pelagic 
fauna. 

"The experiments of using the tow-net at great depths (of 500 and 
1,000 fathoms), as was done by Mr. Murray on the 'Challenger,' were 
not conclusive, as I have already pointed out on a former occasion, while 



SITPrLEMENT. 219 

the so-called deep-sea Siphoiiophone, taken Ironi (he souiidiiig-liiie by 
Dr. Studer, on the 'Gazelle," may have come, as 1 have so often observed 
ill the Caribbean, from any depth. I do not mean, of coarse, to deny 
that there are deep-sea Medusee. The habit common to so many of our 
Acalephs (Tima, ^Equorea, Ptychogena, etc.) of swimmiiig near the bottom 
is well known; Dactylometra moves near the bottom, and Polyclonia 
remains during the day turned up, with the disk downward, on the mud 
bottom. I only wish to call attention to the uncertain methods adopted 
for ascertaining at what depth they live. 

"As far as the pelagic fauna is concerned, those who have been in the 
habit of collecting surface animals know full well that the least ripple 
will send them below the reach of commotion; Muller and Baur were 
the first to adopt the use of a tow-net sunk below the surface to collect 
pelagic animals when the water was disturbed. It seems natural to pre- 
sume, as we have found from our experiments witli tlie Sigsbee cylinder, 
that this surface fauna only sinks out of reach of the disturbances of the 
top, and does not extend downward to any great depth. The dependence 
of all the pelagic forms upon food which is most abundant at the surface, 
or near it, would naturally keep them Avhere they found it in greatest 
quantity. 

"Of course, with the death and decomposition of the pelagic forms, 
they sink to the bottom fast enough to form an important part of the food 
supply of the deep-sea animals, as can easily be ascertained by examining 
the intestines of the deep-water Echinoderms. The variety and abundance 
of the pelagic fauna, and its importance as food for marine animals, are 
as yet hardly realized. 

•' One must have sailed through miles of Salpte with the associated 
Crustacean, Annelid, and Mollusk larvae, the Acalephs, especially the 
oceanic Siphonophores, the Pteropods and Heteropods, with the Radio- 
larians, Globigerina?, and Algas, to form some idea how rich a field still 
remains to be explored. The variety of the pelagic fauna in the course 
of the Gulf Stream is probably not surpassed by that of any other part of 
the ocean." 



220 SUPPLEMENT. 

PRESSURE ERRORS OF MILLER-CASELLA THERMOMETERS. 

The following report is taken from "JVatiire,'' issue of April 21, 
1881, page 595. It treats of a matter contained in the original volume 
on Deep-Sea Sounding and Dredging, page 109: 

"Royal Society, April 4^. 
"Professor Tait communicated the results of his experiments on the 
pressure errors of the Challenger thermometers, the correction for which, 
as originally furnished to the expedition, was 0°.5 F. per mile of depth. 
The mode of experimenting was to subject the thermometers to consider- 
able pressure in a hydraulic press, which was essentially a strong steel 
cylinder that was warranted to stand a pressure of 25 tons weight on the 
square inch. It was supported in an upright position upon a strong 
tripod stand. Water was filled in from above; and into the upper end of 
the cylinder there was lowered a tight-fitting plug, which was fixed in 
position by a transverse steel bolt. The lower end of the cylinder was 
connected through a narrow copper tube to a hydraulic pump, which, by 
pumping in water to the cylinder, raised the pressure to the required 
amount. At three tons pressure an average effect of 1°.5 F. was produced 
upon the inclosed thermometers. Before drawing any conclusions as to the 
correction to be applied in deep-sea sounding, it was necessary to consider 
how far this effect could be explained as resulting from the peculiar con- 
ditions under which the experiments were made. From the known com- 
pressibility of glass it was calculated that the volume of the bore of a 
thermometer tube, closed at both ends, would be diminished by only one- 
thousandth part for an increase of pressure of one ton weight on the square 
inch ; and from a direct experiment made with a metre-long tube this was 
proved to represent very approximately the real effect. Hence it was quite 
out of the question that this could have any appreciable effect on such 
comparatively short thermometers as those of the Challenger, which were 
besides subject to much graver errors, such as those arising from the 
shifting of the indices during the ascent from the depths, or even from 
the effect of parallax when taking the reading. The direct action of 



SUPPLEIMENT. 221 

pressure may then be disregarded, and the effect prodaed upon the tlier- 
mometers in the compression apparatus must be due to secondary effects 
of pressure, such as evolution of heat. The various sources of heat Averc 
four: 1. Heating of. the water by compression. This depends greatly on 
the original temperature of the water, being nil at the point of maximum 
density (40° F.) and larger for higher temperatures. One-fourth of the 
total effect is due to this. 2. Heating of the water due to pumping in 
through the narrow tube. This accounts for three-twentieths of the 
effect, 3. Heating of the vulcanite frame by compression. This explains 
another fifth. 4. Heating due to the effect upon the protecting-bulb. 
This probably explains the remaining two-fifths of the effect. In this 
last case, however, there is not only compression but distortion; and of 
the thermal effects of such a strain no one yet knows anything. These 
four sources of error cannot be supposed to exist under the conditions in 
which deep-sea temperatures are taken ; and the only other possible source, 
that, namely, due to the direct effect of pressure, gives rise to an error 
which requires a correction of only 0°.04 F. per mile of depth. In the 
course of the description of experiments Professor Tail had occasion to 
describe the various kinds of pressure gauges which he had found it 
necessary to devise, the ordinary forms of gauge being altogether useless 
for scientific work." 



85 




"% 



THE PLOTTING OF A LINE OF SOUNDENG S 



36 





FOR SOUNDING WITH WIRE; 
LIEUT. COMDR. C.D.SICSBEE.U.S.N.. ASSISTANT, C S 



37 



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38 




u s COAST SURVEY DEEP-SEA SOUNU]NG AND DREDGING 




39 





NI) DREDGING 




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S. COAST SURVEY 



DKEP-SF.A SOUNDING AND DRF^DdlNG 








41 



US. COAST siTHVKY DEEP-SEA SOUNDING AliP DREDGING 




•noixviioa 'ivioi^i^o 




